Important Descriptive Question with answer



Computer is a fast and accurate electronic machine which accepts and store information, processes the information based on instructions given to it and produces the desired results. Apart from these functions we can type letter, draw pictures, make graphics, listen to music, see movies and also play game.

Computer - Commonly Operated Machine Particularly Used for Technical and Education Research

A Computer is an electronic machine that can solve different problems, process data, store & retrieve data and perform calculations faster and efficiently than humans

-Charles Babbage is called the "Grand Father" of the computer. The First mechanical computer designed by Charles Babbage was called Analytical Engine. It uses read-only memory in the form of punch cards.

-Computer is an advanced electronic device that takes raw data as input from the user and processes these data under the control of set of instructions (called program) and gives the result (output) and saves output for the future use. It can process both numerical and non-numerical (arithmetic and logical) calculations.

Characters of Computer

  1. High Speed-:
  2. Speed of a computer device is very fast as it can perform in a few seconds, the amount of calculation or anything that we are human being can do in an entire year or more. 2 gigahertz to 4 gigahertz is the speed range of computer device
  3. Accuracy-:
  4. Accuracy of a computer is consistent. Computer gives us accurate result or calculation. Error occurs in result for any calculation in a computer are only due to wrong program or instruction, inaccuracy in input data etc. You can directly say that errors in computers can happen only due to human beings. Otherwise the accuracy of a computer device is constantly high.
  5. Consistency-:
  6. Computer is a consistent machine; it means that computer never gets tired of working more. You can use computer to perform your task without any error for any number of hours, any number of hours means you can use your computer system continuously for 24 hours a day and 365 days a year.
  7. Data Storage Capacity-:
  8. Computer can store huge amount of data in a small sized storage disk such as hard disk, CD, DVD, Pen Drive, memory card etc
  9. Versatility-:
  10. The computer system is very versatile machine. The most wonderful feature of the activities of different types from simple calculation to the complex scientific operations and computations and is also capable of preparing the examination marks sheets, bills, letters, documents, and also the design and modelling of navigating missiles and satellites.
  11. Automation-:
  12. The word automation is conjoint with the computer for a particular task, the computer does not fully depend on the user, but it proceeds the task in forward direction automatically till its completion. Computers can be easily programmed to perform a series of task according to the requirements. The computer automatically executes these instructions sequentially, if any error occurs, it produces the appropriate error message
  13. Flexibility-:
  14. Flexibility means that a computer can work in many areas like you can use your computer system to:
    • Watch movies or videos
    • Listen sounds or music's
    • Play games
    • See pictures
    • Write textual documents and save
    • Open and read anything
    • and many more
  15. Remembrance Power-:
  16. The computer can store and recall the information at any time because of the presence of the secondary storage devices, but this is not possible with the human beings

Advantages of Computer

  1. Increase your productivity -
  2. Computers increase your productivity and, with a good understanding of the software running on them, you will become more productive at everything you do. For example, once you have a basic understanding of using a word processor, you can create, store, edit, share, and print documents and letters. Each of these things was either impossible or much slower with all pre-existing technologies.
  3. Connects you to the Internet -
  4. Connecting a computer to the Internet is what unlocks the full potential of a computer. Once connected, your choices and available options are almost limitless
  5. Can store vast amounts of information and reduce waste-
  6. Computers are capable of storing and accessing vast amounts of information. For example, a computer and devices like eBook readers can store hundreds or thousands of books, given enough storage capacity. By being able to store books, documents, movies, pictures, and songs digitally, you can quickly find what you need with a search and share information between devices. It eliminates the need for paper and plastics used to make non-digital versions of the media
  7. Helps sort, organize, and search through information-
  8. A computer can use its stored information more efficiently than any other device. In our earlier example, we mentioned the ability to store thousands of books. Once those books are stored on a computer, they can be sorted into categories, alphabetized, and then searched to find exactly what you are looking for in less than a minute. Trying to find the same text in a thousand books would take a human month, if not years.
  9. Get a better understanding of data-
  10. Computers can also give you a better understanding of data and big data. For example, a business could have a database of items they've sold. Using that data, they can quickly identify what items sell best at what time of year, when to mark up or down an item, and what items are not selling. Having access to this type of information can give the business a better understanding of their customers and a competitive edge against their competitors.
  11. Keeps you connected -
  12. Computers can help keep you connected with long distance friends and family over e-mail and social networking. You can also connect with millions of other people that share the same interests as you through online forums, chat, and VoIP services, like Skype. Being able to connect to people all around the world is also an excellent way to meet people you would normally never meet. Another great thing about communication on the Internet is that it's fast compared to other forms of communication. For example, you could send someone an e-mail on the other side of the planet, and have it arrive in less than a few minute. Snail mail (postal mail) could take days or even weeks to arrive.
  13. Can help you learn and keep you informed -
  14. The computer connected to the Internet is a great learning tool and something that can help answer almost any question, teaching you anything that interests you. You can also access news around the world to keep up-to-date with all of the latest news, weather, and stories around the world. You could learn a new profession by reading websites or watching videos. You could even sign up for online courses that teach you about any subject you'd learn in school
  15. Can make you money -
  16. When connected to the Internet, a computer can help you make money many different ways. For example, it is much cheaper to create and run an online store than having a physical store. Also, once online, your store or product has a global audience and you could sell to anyone in the world
  17. Improves your abilities-
  18. Are you not the best speller, have poor grammar, not great at math, don't have a great memory, or need help with something else? By using all of a computer's abilities, you can improve all your abilities, or if you have a hard time learning, you can rely on the computer to assist you.
  19. Save time -
  20. Today, there are many services that can help save you time. Several examples are listed below. Amazon, Trivago, Google Map, Internet-Banking, Swiggy etc.

Limitation of Computer

  1. Depend on users input.
  2. Computer have no imagination.
  3. Cannot detect error in logic.
  4. Only expert user can work on it.
  5. Cannot take its own decisions.
  6. No Self-Intelligence
  7. No Thinking and Decision Making Power
  8. No Feeling
  9. No learning power

Types of Computers

There are different types of Computers with respect to size, speed, storage capacity and cost, computer can be classified in the following types-

  • Micro Computer
  • Mini Computer
  • Mainframe Computer
  • Super Computer
1. Micro Computer-
These computers are small in size and cost less. They are usually designed for personal use therefore they are also called personal computer. They are mainly used in homes, schools, offices, shops, banks, etc. Examples are: Commodore 64, IBM PC. These computers are given different names according to their usage.

Types of Micro Computers

Desktop: - These computers can easily be accommodated on the top of a desk due to their small size. Hence they are also called desktop computer.
Laptop: - These computers are small in size and can be placed on the lap. These are battery operated computers and can be carried in briefcase and used anywhere while travelling.
Handheld: - These are the smallest computer, also called PDAs (Personal digital assistant). They lack the power of a desktop or laptop computers, but offer features for users who need limited functions and small size.

2. Mini Computer-
These computers are bigger in size than that of Micro Computers.
They have a higher processing speed and are costlier than Micro Computers.
Several users can use it at the same time.
They are used in banks, universities and in big organizations. Example, PDP-8

3. Mainframe Computer-
These computers are very powerful.
They are big in size with a large memory and high speed.
They are designed to tackle huge amount of data.
More than hundred users can use a mainframe computer simultaneously. They are used in networked environment.
Mainframe computer are very expensive and can be used in large business organizations, universities, banks scientific laboratories, airline/ railway ticket reservation, state exchange markets etc.

4. Super Computer-
They are the most powerful computers with a huge processing speed.
These computers are used for weather forecasting space research, satellite control etc. Examples are CRAY-1, CRAY2, PARAM, ETA, A-10 etc.
Abacus was the first calculation device.
Charles Babbage is considered to be the father of computes. He invented difference engine in 1822 and analytical engine in 1833.
Augusta Ada was the first programmer.
ENIAC (Electronic Numerical Integrator and Computer) was the first general purpose electronic digital computer.
UNIVAC (Universal Automatic Computer) was the first computer to handle both numeric and text data.
Computers are categorized into four types with respect to speed, storage capacity, size and cost.

Application of Computer

Application of computers in various fields.
1. Business -
A computer has high speed of calculation, diligence, accuracy, reliability, or versatility which has made it an integrated part in all business organizations. Computer is used in business organizations for −
  • Payroll calculations
  • Budgeting
  • Sales analysis
  • Financial forecasting
  • Managing employee database
  • Maintenance of stocks, etc.
2. Banking -
Today, banking is almost totally dependent on computers. Banks provide the following facilities −
  • Online accounting facility, which includes checking current balance, making deposits and overdrafts, checking interest charges, shares, and trustee records.
  • ATM machines which are completely automated are making it even easier for customers to deal with banks.
3. Insurance -
Insurance companies are keeping all records up-to-date with the help of computers. Insurance companies, finance houses, and stock broking firms are widely using computers for their concerns. Insurance companies are maintaining a database of all clients with information showing −
  • Procedure to continue with policies
  • Starting date of the policies
  • Next due installment of a policy
  • Maturity date
  • Interests due
  • Survival benefits
  • Bonus
4. Education -
The computer helps in providing a lot of facilities in the education system.
  • The computer provides a tool in the education system known as CBE (Computer Based Education).
  • CBE involves control, delivery, and evaluation of learning.
  • Computer education is rapidly increasing the graph of number of computer students.
  • There are a number of methods in which educational institutions can use a computer to educate the students.
  • It is used to prepare a database about performance of a student and analysis is carried out on this basis.
5. Marketing -
In marketing, uses of the computer are following −
  • Advertising − With computers, advertising professionals create art and graphics, write and revise copy, and print and disseminate ads with the goal of selling more products.
  • Home Shopping − Home shopping has been made possible through the use of computerized catalogues that provide access to product information and permit direct entry of orders to be filled by the customers.
Healthcare -
Computers have become an important part in hospitals, labs, and dispensaries. They are being used in hospitals to keep the record of patients and medicines. It is also used in scanning and diagnosing different diseases. ECG, EEG, ultrasounds and CT scans, etc. are also done by computerized machines. Following are some major fields of health care in which computers are used.
  • Diagnostic System − Computers are used to collect data and identify the cause of illness.
  • Lab-diagnostic System − All tests can be done and the reports are prepared by computer.
  • Patient Monitoring System − These are used to check the patient's signs for abnormality such as in Cardiac Arrest, ECG, etc.
  • Pharma Information System − Computer is used to check drug labels, expiry dates, harmful side effects, etc.
  • Surgery − Nowadays, computers are also used in performing surgery.
7. Engineering Design-
Computers are widely used for Engineering purpose. One of the major areas is CAD (Computer Aided Design) that provides creation and modification of images. Some of the fields are −
  • Structural Engineering − Requires stress and strain analysis for design of ships, buildings, budgets, airplanes, etc.
  • Industrial Engineering − Computers deal with design, implementation, and improvement of integrated systems of people, materials, and equipment.
  • Architectural Engineering − Computers help in planning towns, designing buildings, determining a range of buildings on a site using both 2D and 3D drawings.
8. Military -
Computers are largely used in defence. Modern tanks, missiles, weapons, etc. Military also employs computerized control systems. Some military areas where a computer has been used are −
  • Missile Control
  • Military Communication
  • Military Operation and Planning
  • Smart Weapons
9. Communication -
Communication is a way to convey a message, an idea, a picture, or speech that is received and understood clearly and correctly by the person for whom it is meant. Some main areas in this category are −
  • E-mail
  • Chatting
  • Usenet
  • FTP
  • Telnet
  • Video-conferencing
10. Government -
Computers play an important role in government services. Some major fields in this category are −
  • Budgets
  • Sales tax department
  • Income tax department
  • Computation of male/female ratio
  • Computerization of voters lists
  • Computerization of PAN card
  • Weather forecasting

Data Representation -

Data Representation refers to the form in which data is stored, processed, and transmitted.

  1. Number System
    • Decimal Number System:
    • There are 10 digits i.e 1, 2, 3, 4, 5, 6, 7, 8, 9 available in decimal number system. It is known as Base 10 system. The value of a digit in a number depends upon its position in the number e.g. the number 546 in this system is represented as (546)10 546 = (4*102) + (8*101) + (6*100)
    • Binary Number System
    • The Binary Number System contains 2 unique digits 0 and 1. it is known as Base 2 system.
    • Octal Number System
    • There are 8 unique digits available in octal number system. These are 0, 1, 2, 3, 4, 5, 6, 7. thus, any number formed is the combination of these digits. It is known as Base 8 system.
    • Hexadecimal Number System
    • There are 16 unique digits available in Hexadecimal number system. These are 0, 1, 2, 3, 4, 5, 6, 7, 8, A, B, C, D, E, F where A denotes 10, B denotes 11………,F denotes 15. thus any number formed is a combination of these digits. It is known as Base 16 system.

  2. Text System
    • ASCII – American Standard Code for Information Interchange
    • Initially ASCII coding system used 7-bit binary digit. 128 characters can be represented using this coding system. ASCII is used to represent text. (Appendix - Table 3.17) ASCII system is designed and approved by ANSI (American National Standard Institute)
      When the word ‘School’ is entered into the computer through the keyboard, write down how it is understood by the computer.
      Step:1 First, write the decimal numbers for the symbols.
      S - 83 c - 99 h - 104 o - 111 l - 108
      Step:2 Write binary numbers for each value. S - 1010011 c – 1100011 h - 1101000 o - 1101111 l - 1101100
      Step:3 Write the associated code
      S c h o o l
    • Unicode System
    • Though 128 characters can be used in the ASCII system and 256 characters can be used in the EBCDIC system for data representation. For example, these systems cannot be used for Sinhala, Japanese, Chinese and Tamil languages as there are more than 256 characters. Hence Unicode system was designed according to a standard to represent 65536 different symbols of 16 bits (216 = 65536).
      Unicode system uses unique number for each number, text or symbol in any or Operating System

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Classification of Computer Parts

  • Hardware
  • Software
  1. Hardware:-
  2. All physical parts of computer that we can touch or feel is called "HARDWARE".

    Types of Hardware device

    • Input Device
    • In which device we feed data into the Computer is called Input Device. Most commonly input device are Mouse & Keyboard.
      1. Joystick
      2. Mouse
      3. Keyboard
      4. Scanner
      5. LightPen
      6. Touchpad
      7. Etc..
    • Output Device
    • In which device we get the result is called Output Device
      1. Monitor
      2. Printer
      3. Speaker
      4. Plotter
      5. Etc..
  3. Software:-
  4. Software is a set of Program that we can’t touch or feel.
    Software is a set of instructions, data or programs used to operate computers and execute specific tasks

    Types of Software

    1. System Software (Operating System)
    2. Application Software

    1. System Software (Operating System)
    Operating system is needed to operate a computer. An operating system controls the overall activities of a computer. It acts as a link between the user and the hardware and enables them to work together.
    An Operating System (OS) is an interface between a computer user and computer hardware. An operating system is a software which performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers
    Sr No.OS NameCompany Name
    1 Windows Microsoft
    1 MAC Apple
    1 iOS Apple
    1 Android Google
    1 Symboin Nokia

    important functions of an operating System.

    • Memory Management
    • Memory management refers to management of Primary Memory or Main Memory. Main memory is a large array of words or bytes where each word or byte has its own address.
      Main memory provides a fast storage that can be accessed directly by the CPU. For a program to be executed, it must in the main memory. An Operating System does the following activities for memory management −
      • Keeps tracks of primary memory, i.e., what part of it are in use by whom, what part are not in use.
      • In multiprogramming, the OS decides which process will get memory when and how much.
      • Allocates the memory when a process requests it to do so.
      • De-allocates the memory when a process no longer needs it or has been terminated.

    • Processor Management
    • In multiprogramming environment, the OS decides which process gets the processor when and for how much time. This function is called process scheduling. An Operating System does the following activities for processor management −
      • Keeps tracks of processor and status of process. The program responsible for this task is known as traffic controller.
      • Allocates the processor (CPU) to a process.
      • De-allocates processor when a process is no longer required.

    • Device Management
    • An Operating System manages device communication via their respective drivers. It does the following activities for device management −
      • Keeps tracks of all devices. Program responsible for this task is known as the I/O controller.
      • Decides which process gets the device when and for how much time.
      • Allocates the device in the efficient way.
      • De-allocates devices.

    • File Management
    • A file system is normally organized into directories for easy navigation and usage. These directories may contain files and other directions.
      An Operating System does the following activities for file management −
      • Keeps track of information, location, uses, status etc. The collective facilities are often known as file system.
      • Decides who gets the resources.
      • Allocates the resources.
      • De-allocates the resources.

    • Other Important Activities
    • Following are some of the important activities that an Operating System performs −
      • Security −
      • By means of password and similar other techniques, it prevents unauthorized access to programs and data.
      • Control over system performance −
      • Recording delays between request for a service and response from the system.
      • Job accounting −
      • Keeping track of time and resources used by various jobs and users.
      • Error detecting aids −
      • Production of dumps, traces, error messages, and other debugging and error detecting aids.
      • Coordination between other softwares and users −
      • Coordination and assignment of compilers, interpreters, assemblers and other software to the various users of the computer systems.

      2. Application Software
      Application software is a program or group of programs designed for end users. These programs are divided into two classes: system software and application software. While system software consists of low-level programs that interact with computers at a basic level, application software resides above system software and includes applications such as database programs, word processors and spreadsheets. Application software may be bundled with system software or published alone.
      Application software may simply be referred to as an application.
      1. MS Office
      2. Tally
      3. Google Chrome
      4. UC Browser
      5. WhatsApp
      6. Etc.

  • Firmware:-
  • Firmware is a software program or set of instructions programmed on a hardware device. It provides the necessary instructions for how the device communicates with the other computer hardware. But how can software be programmed onto hardware? Good question. Firmware is typically stored in the flash ROM of a hardware device. While ROM is "read-only memory," flash ROM can be erased and rewritten because it is actually a type of flash memory.

  • Liveware:-
  • Liveware is a term to describe the human system, opposed to hardware or software in a computer.
    Human beings or their brains, when regarded as a form of computer hardware or software.
    Liveware was used in the computer industry as early as 1966 to refer to computer users, often in humorous contexts, by analogy with hardware and software. A slang term used to denote people using computers, and is based on the need for a human, or liveware, to operate the system using hardware and software. Other words meaning the same or similar to liveware include wetware, meatware and jellyware. Meatware and jellyware are most often used by internal customer support personnel as slang terms when referencing human operating errors. The term liveware is found in the Culture novels by Iain M. Banks. A Culture Ship is named "Liveware Problem". This is likely a pun on a common computing jargon hinting at the fact that the problem lies with the system's user.

    Translator :- A program written in high-level language is called as source code. To convert the source code into machine code, translators are needed.
    A translator takes a program written in source language as input and converts it into a program in target language as output.
    It also detects and reports the error during translation.
    Roles of translator are:
    • Translating the high-level language program input into an equivalent machine language program.
    • Providing diagnostic messages wherever the programmer violates specification of the high-level language program.

    There are three types of translator

    The Assembler is used to translate the program written in Assembly language into machine code. The source program is a input of assembler that contains assembly language instructions. The output generated by assembler is the object code or machine code understandable by the computer.

    The language processor that reads the complete source program written in high level language as a whole in one go and translates it into an equivalent program in machine language is called as a Compiler.
    Example: C, C++, C#, Java

    The translation of single statement of source program into machine code is done by language processor and executes it immediately before moving on to the next line is called an interpreter. If there is an error in the statement, the interpreter terminates its translating process at that statement and displays an error message. The interpreter moves on to the next line for execution only after removal of the error. An Interpreter directly executes instructions written in a programming or scripting language without previously converting them to an object code or machine code.
    Example: Perl, Python and Matlab.

    Difference between Compiler and Interpreter

    SRCompiler Interpreter
    1 A compiler is a program which coverts the entire source code of a programming language into executable machine code for a CPU. interpreter takes a source program and runs it line by line, translating each line as it comes to it.
    2 Compiler takes large amount of time to analyze the entire source code but the overall execution time of the program is comparatively faster. Interpreter takes less amount of time to analyze the source code but the overall execution time of the program is slower.
    3 Compiler generates the error message only after scanning the whole program, so debugging is comparatively hard as the error can be present any where in the program. Its Debugging is easier as it continues translating the program until the error is met
    4 Generates intermediate object code. No intermediate object code is generated.
    5 Examples: C, C++, Java Examples: Python, Perl


    What is an Information System ?

    Many organizations work with large amounts of data. Data are basic values or facts and are organized in a database. Many people think of data as synonymous with information; however, information actually consists of data that has been organized to help answers questions and to solve problems. An information system is defined as the software that helps organize and analyze data. So, the purpose of an information system is to turn raw data into useful information that can be used for decision making in an organization.


    "Information systems (IS) is the study of complementary networks of hardware and software that people and organizations use to collect, filter, process, create, and distribute data"

    "Information systems are combinations of hardware, software, and telecommunications networks that people build and use to collect, create, and distribute useful data, typically in organizational settings"

    "Information systems are interrelated components working together to collect, process, store, and disseminate information to support decision making, coordination, control, analysis, and viualization in an organization"

    Typical Components of Information Systems

    1. Computer Hardware
    2. Physical equipment used for input, output and processing. What hardware to use it depends upon the type and size of the organisation. It consists of input, an output device, operating system, processor, and media devices. This also includes computer peripheral devices
    3. Computer Software
    4. The programs/ application program used to control and coordinate the hardware components. It is used for analysing and processing of the data. These programs include a set of instruction used for processing information.
      Software is further classified into 3 types:
      • System Software
      • Application Software
      • Procedures
    5. Databases
    6. Data are the raw facts and figures that are unorganised that are and later processed to generate information. Softwares are used for organising and serving data to the user, managing physical storage of media and virtual resources. As the hardware can’t work without software the same as software needs data for processing. Data are managed using Database management system.
      Database software is used for efficient access for required data, and to manage knowledge bases.
    7. Network
      • Networks resources refer to the telecommunication networks like the intranet, extranet and the internet.
      • These resources facilitate the flow of information in the organisation.
      • Networks consists of both the physicals devises such as networks cards, routers, hubs and cables and software such as operating systems, web servers, data servers and application servers.
      • Telecommunications networks consist of computers, communications processors, and other devices interconnected by communications media and controlled by software.
      • Networks include communication media, and Network Support.
    8. Human Resources
    9. It is associated with the manpower required to run and manage the system. People are the end user of the information system, end-user use information produced for their own purpose, the main purpose of the information system is to benefit the end user. The end user can be accountants, engineers, salespersons, customers, clerks, or managers etc. People are also responsible to develop and operate information systems. They include systems analysts, computer operators, programmers, and other clerical IS personnel, and managerial techniques

    Why Business Need Information Systems

    Many businesses today do not make use of internet which is very important in this day. Upgrading the computer information system is not an option in this technology-driven era, it is essential. The follow are reasons why businesses need to use information systems.
    1. Operational Excellence:
    2. In order for a business to achieve high levels of profitability, they need to improve the efficiency of their operations. Information systems is a tool that is used in order to achieve high levels of efficiency and productivity in business operations.
    3. New Products, Services and Business Models:
    4. Information systems can be used to create new products and services and also an entirely new business model. A business model describes how a company produces, delivers and how they sell a product or service to create wealth.
    5. Customer/Supplier Intimacy:
    6. When a business provides a good product or service customers tend to return and purchase more frequently which raises revenue and profits. The more a business engages with its suppliers, the better the supplier can provide vital inputs which can lower costs.
    7. Improved Decision-Making:
    8. Many managers who operation in an information bank may never have the right information at the right time to make an informed decision. This can raise costs and lose customers. However, information systems allow the managers to use real-time data from the marketplace when making decision.
    9. Competitive Advantage:
    10. When a firm achieved one or more of these business objectives (operational excellence, new products, services and business models, customer/supplier intimacy and improved decision-making), they may have a competitive advantage. By performing better than competitors, charging less for superior goods and responding to customers and suppliers, higher sales and profits can be made.
    11. Day To Day Survival:
    12. Businesses must invest in information systems and technology as they are essential to doing business. This necessity is caused by the industry level changes and firms need to use information systems and technology in order to provide the capability to respond to these.
      Information systems enables companies to react, respond, cater, store, retrieve, disseminate and control their new valuable asset that is information. In the future, a good information system in a business will no longer be an option, it will become a compulsory in determining success.

    Types of information systems

    1. Transaction Processing Systems (TPS):
    2. A Transaction Processing Systems (TPS) is used primarily for record keeping which is required in any organization to conduct the business. Examples of TPS are sales order entry, payroll, and shipping records etc. TPS is used for periodic report generation in a scheduled manner. TPS is also used for producing reports on demand as well as exception reports.
    3. Decision Support System (DSS):
    4. Decision Support System (DSS) serves the management of an organization. A decision support system has sophisticated data analysis tools, which support and assist all aspects of problem-specific decision-making. DSS may use data from external sources such as current stock prices to enhance decision-making. DSS is used when the problem is complex and the information needed to make the best decision is difficult to obtain and use. DSS is developed with the help of decision-makers in an organization. DSS helps in the appropriate decision-making process and does not make any decision.
    5. Executive Information System (EIS):
    6. An Executive Information System (EIS) is also called the Executive Support System. Senior managers of an organization use the EIS. Therefore, it must be easy to use so that executives can use it without any assistance. EIS can do trend analysis, exception reporting and have drill-down capabilities. The results are usually presented in a graphical form tailored to the executive’s information needs. EIS has on-line analysis tools and they access a broad range of internal and external data.
    7. Management Information Systems (MIS):
    8. Management Information System (MIS) provides the management routine summary of basic operations of the organization. The essential services are recorded by the TPS of the organization and MIS consolidates the data on sales, production etc. MIS provides routine information to managers and decision makers. The primary objective behind installing an MIS in the organization is to increase operational efficiency. MIS may support marketing, production, finance, etc.
    9. Workflow System:
    10. A workflow system is a rule-based management system that directs, coordinates and monitors the execution of an interrelated set of tasks arranged to form a business process. There are three types of workflow software. They are:
      1. Administrative workflow systems focus on the tracking of expense reports, travel requests, messages.
      2. An Ad-hoc workflow system deals with the shaping of product, sales proposals and strategic plans.
      3. Production workflow systems are concerned with mortgage loans and insurance claims.
        A workflow system may be Internet-based and may be combined with e-mail. A workflow system may be based on server architecture that may use a database or file server.
    11. Enterprise Resource Planning (ERP):
    12. Enterprise Resource Planning (ERP) system is a business process management software that allows an organization to use a system of integrated programs capable of managing a company’s vital business operations for an entire multi-site, global organization.
    13. Expert Systems:
    14. The expert systems have the ability to make suggestions and act like an expert in a particular field of an organization. An expert system has an extensive knowledge base.,

    Integration of Information Systems Planning With Overall Business Planning

    1. Identify objectives and challenges:
    2. First step in planning of IT infrastructure is to identify the objectives and the challenges involved in the business in general and information systems in par¬ticular. This is achieved by enlisting the broad objectives, business functions and processes, business resource requirements, etc.
      In the light of these business objectives and requirements, information systems issues may be identified after careful assessment of exist¬ing IT infrastructure. In the process, a status report may be pre¬pared that incorporates the broad business and information sys¬tem objectives, the assessment of present resources and gaps in the requirements in general terms.
    3. Business and information systems planning:
    4. The second step is to review the business planning process in the light of changing business scenario and identify the business functions that need greater support from information systems.
      Objectives of the IT in¬frastructure may be defined keeping in view the functions to be automated. Linking the information system issues with strategic inputs is essential element of this step.
      Thus, the objectives of the information system should focus on the strategic inputs to various business processes. Bucklandsuggests that a correlation analysis may be conducted between the information system issues and stra¬tegic inputs.
      For example, the information issues like which busi¬ness function must be supported by information systems may be correlated with business strategic inputs, such as technology fore¬cast, strategic assumptions and business plan analysis. In addition to the broad strategic inputs, both for the business process and in¬formation systems, critical success factors for each information sys¬tem project should be identified and agreed upon.
    5. Identifying alternatives:
    6. Once the objectives of the information sys¬tems are defined, the alternative strategies for IT solutions need to be identified. These alternatives may require identifying alternatives re¬garding the organisation structure, computer hardware, software and networking strategies for achieving the objectives set forth earlier.
    7. Determine priorities:
    8. The next step would be to evaluate each alternative strategy defined in the preceding step with the help of an established criterion.
      The evaluation process shall help in determining the resource require¬ment for each information system project. The priority ranking may have to be changed later in view of the new options that might have been opened. The ranking may be based on priority by the business needs or the estimated impact on the bottom-line. On the basis of the ranking, recommendations may be made for funds allocation.
    9. Draw operational plan:
    10. Once the fund allocation recommenda¬tions have been accepted the operational plans need to drawn in detail. These operational plans may include identifying the hard¬ware needs, planning for system development life cycle, and other IT resources needed for the accepted information system projects.



    In simple words data can be facts related to any object in consideration.
    For example your name, age, height, weight, etc are some data related to you.
    A picture , image , file , pdf etc can also be considered data.


    Database is a systematic collection of data. Databases support storage and manipulation of data. Databases make data management easy. Let's discuss few examples.
    - An online telephone directory would definitely use database to store data pertaining to people, phone numbers, other contact details, etc.
    - Your electricity service provider is obviously using a database to manage billing , client related issues, to handle fault data, etc.
    - Let's also consider the facebook. It needs to store, manipulate and present data related to members, their friends, member activities, messages, advertisements and lot more.
    A database is a collection of related data which represents some aspect of the real world. A database system is designed to be built and populated with data for a certain task.

    Database System/Database Management System

    The software which is used to manage database is called Database Management System (DBMS). For Example, MySQL, Oracle etc.

    Database Management System (DBMS) is a software for storing and retrieving users' data while considering appropriate security measures. It consists of a group of programs which manipulate the database. The DBMS accepts the request for data from an application and instructs the operating system to provide the specific data. In large systems, a DBMS helps users and other third-party software to store and retrieve data.

    DBMS allows users to create their own databases as per their requirement. The term “DBMS” includes the user of the database and other application programs. It provides an interface between the data and the software application.

    Organizing Data in a Traditional File Environment

    Computer systems organize data in a hierarchy that begins with bits and bytes and progresses to more complex groupings of data:
    1. Fields:
    2. Group of characters, words, or a complete number
    3. Records:
    4. Group of related fields, describes an entity (a person, place or thing about which information must be kept - each characteristic of an entity is an attribute
    5. File:
    6. Group of records of the same type
    7. Database:
    8. Group of related files

    Evolution of Database

    Data modeling and databases evolved together, and their history dates back to the 1960’s.
    The database evolution happened in five “waves”
    1. The first wave consisted of network, hierarchical, inverted list, and (in the 1990’s) object-oriented DBMSs; it took place from roughly 1960 to 1999.
    2. The relational wave introduced all of the SQL products (and a few non-SQL) around 1990 and began to lose users around 2008.
    3. The decision support wave introduced Online Analytical Processing (OLAP) and specialized DBMSs around 1990, and is still in full force today.
    4. The graph wave began with The Semantic Web stack from the Worldwide Web Consortium in 1999, with property graphs appearing around 2008
    5. The NoSQL wave includes big data and much more; it began in 2008.

    UNIT V


    - A network, is a collection of computers and other hardware components interconnected by communication channels that allow sharing of resources and information.


    - Networking is the practice of linking two or more computing devices together for the purpose of sharing data. Networks are built with a mix of computer hardware and computer software.

    Advantages of Networking

    -Computer systems and peripherals are connected to form a network. They provide numerous advantages

    • Resource sharing such as printers and storage devices
    • Exchange of information by means of e-Mails and FTP
    • Information sharing by using Web or Internet
    • Interaction with other users using dynamic web pages
    • IP phones
    • Video conferences
    • Parallel computing
    • Instant messaging

    Computer Networking

    computer network is a set of connected computers. Computers on a network are called nodes. The connection between computers can be done via cabling, most commonly the Ethernet cable, or wirelessly through radio waves. Connected computers can share resources, like access to the Internet, printers, file servers, and others. A network is a multipurpose connection, which allows a single computer to do more.

    Classification of Computer Networks

    1. Geographical span
    2. Inter-connectivity
    3. Administration
    4. Architecture

    1. Geographical Span

    • It may be spanned across your table, among Bluetooth enabled devices,. Ranging not more than few meters.
    • It may be spanned across a whole building, including intermediate devices to connect all floors.
    • It may be spanned across a whole city.
    • It may be spanned across multiple cities or provinces.
    • It may be one network covering whole world.

    2. Inter-Connectivity

    Components of a network can be connected to each other differently in some fashion. By connectedness we mean either logically , physically , or both ways.

    • Every single device can be connected to every other device on network, making the network mesh.
    • All devices can be connected to a single medium but geographically disconnected, created bus like structure.
    • Each device is connected to its left and right peers only, creating linear structure.
    • All devices connected together with a single device, creating star like structure.
    • All devices connected arbitrarily using all previous ways to connect each other, resulting in a hybrid structure.

    3. Administration

    From an administrator's point of view, a network can be private network which belongs a single autonomous system and cannot be accessed outside its physical or logical domain. A network can be public which is accessed by all.

    4. Architecture

    Computer networks can be discriminated into various types such as Client-Server, peer-to-peer or hybrid, depending upon its architecture.

    • There can be one or more systems acting as Server. Other being Client, requests the Server to serve requests.
      Server takes and processes request on behalf of Clients.
    • Two systems can be connected Point-to-Point, or in back-to-back fashion. They both reside at the same level and called peers.
    • There can be hybrid network which involves network architecture of both the above types

    Data communications networking

    Data communications refers to the transmission of this digital data between two or more computers and a computer network or data network is a telecommunications network that allows computers to exchange data. The physical connection between networked computing devices is established using either cable media or wireless media. The best-known computer network is the Internet.

    Computer Network Types

    1. Personal Area Network
    2. Local Area Network
    3. Metropolitan Area Network
    4. Wide Area Network
    5. Internet Work

    1. Personal Area Network

    A Personal Area Network (PAN) is smallest network which is very personal to a user. This may include Bluetooth enabled devices or infra-red enabled devices. PAN has connectivity range up to 10 meters. PAN may include wireless computer keyboard and mouse, Bluetooth enabled headphones, wireless printers and TV remotes

    2. Local Area Network

    • A computer network spanned inside a building and operated under single administrative system is generally termed as Local Area Network (LAN). Usually, LAN covers an organization’ offices, schools, colleges or universities. Number of systems connected in LAN may vary from as least as two to as much as 16 million.
    • LAN provides a useful way of sharing the resources between end users. The resources such as printers, file servers, scanners, and internet are easily sharable among computers.
    • LANs are composed of inexpensive networking and routing equipment. It may contains local servers serving file storage and other locally shared applications. It mostly operates on private IP addresses and does not involve heavy routing. LAN works under its own local domain and controlled centrally
    • LAN uses either Ethernet or Token-ring technology. Ethernet is most widely employed LAN technology and uses Star topology, while Token-ring is rarely seen.
    • LAN can be wired, wireless, or in both forms at once.

    3. Metropolitan Area Network

    • The Metropolitan Area Network (MAN) generally expands throughout a city such as cable TV network. It can be in the form of Ethernet, Token-ring, ATM, or Fiber Distributed Data Interface (FDDI).
    • Metro Ethernet is a service which is provided by ISPs. This service enables its users to expand their Local Area Networks. For example, MAN can help an organization to connect all of its offices in a city.
    • Backbone of MAN is high-capacity and high-speed fiber optics. MAN works in between Local Area Network and Wide Area Network. MAN provides uplink for LANs to WANs or internet.

    4. Wide Area Network

    • As the name suggests, the Wide Area Network (WAN) covers a wide area which may span across provinces and even a whole country. Generally, telecommunication networks are Wide Area Network.
    • These networks provide connectivity to MANs and LANs. Since they are equipped with very high speed backbone, WANs use very expensive network equipment.
    • WAN may use advanced technologies such as Asynchronous Transfer Mode (ATM), Frame Relay, and Synchronous Optical Network (SONET). WAN may be managed by multiple administration.

    5. Internet Work

    • A network of networks is called an internet work, or simply the internet. It is the largest network in existence on this planet. The internet hugely connects all WANs and it can have connection to LANs and Home networks. Internet uses TCP/IP protocol suite and uses IP as its addressing protocol. Present day, Internet is widely implemented using IPv4. Because of shortage of address spaces, it is gradually migrating from IPv4 to IPv6.
    • Internet enables its users to share and access enormous amount of information worldwide. It uses WWW, FTP, email services, audio and video streaming etc. At huge level, internet works on Client-Server model.
    • Internet uses very high speed backbone of fiber optics. To inter-connect various continents, fibers are laid under sea known to us as submarine communication cable.
    • Internet is widely deployed on World Wide Web services using HTML linked pages and is accessible by client software known as Web Browsers. When a user requests a page using some web browser located on some Web Server anywhere in the world, the Web Server responds with the proper HTML page. The communication delay is very low.

    Internet Protocol

    The Internet Protocol (IP) is the method or protocol by which data is sent from one computer to another on the Internet. Each computer (known as a host) on the Internet has at least one IP address that uniquely identifies it from all other computers on the Internet.

    Communication Devices

    A communication device is a hardware device capable of transmitting an analog or digital signal over the telephone, other communication wire, or wirelessly.

    • Bluetooth
    • Bluetooth is a computing and telecommunications industry specification that describes how devices can communicate with each other. Devices that use Bluetooth include computers, a computer keyboard and mouse, personal digital assistants, and smartphones.
      Bluetooth is an RF technology that operates at 2.4 GHz, has an effective range of 32-feet (10 meters) (this range varies on the power class), and has a transfer rate of 1 Mbps and throughput of 721 Kbps.

      Below are some other examples of how Bluetooth can be used.
      • Bluetooth headphones-
      • Headphones that can connect to any Bluetooth device.
      • Bluetooth keyboard and Bluetooth mouse -
      • Wireless keyboards and mice.
      • Bluetooth speaker -
      • Speakers that can connect to any Bluetooth audio device.
      • Bluetooth car -
      • A car with Bluetooth can make hands-free calls in the car.
      • Bluetooth watch or Bluetooth health monitor -
      • Bluetooth wrists devices can transmit data over Bluetooth to other devices.
      • Bluetooth lock -
      • Door lock that can allow you to remotely lock and unlock a door.

    • Modem
    • A modem or broadband modem is a hardware device that connects a computer or router to a broadband network. For example, a cable Modem and DSL modem are two examples of these types of Modems.

      A broadband modem is an external device that connects to your computers and other network devices using either a network cable or over a wireless connection.

      History of the modem
      The first modem, known as the Dataphone, was released by AT&T in 1960. It later became more common for home users when Dennis Hayes and Dale Heatherington released the 80-103A modem in 1977.
      Dial-up modems were commonly used by computers to connect to the Internet through the early 2000s until broadband Internet started to be more widely available. As broadband Internet became more popular and available, dial-up modems were used by fewer computer users. Today, computers no longer come with a dial-up modem, requiring users who need one to purchase and install it.

      Types of computer Modems
      Below are the four versions of a computer modem found in computers.
      • Onboard modem -
      • Modem built onto the computer motherboard. These modems cannot be removed but can be disabled through a jumper or CMOS setup.
      • Internal modem -
      • Modem that connects to a PCI slot inside a newer desktop computer or ISA slot on an older computer. The internal modem shown at the beginning of this document is an example of a PCI modem.
      • External modem -
      • Modem within a box that connects to the computer externally, usually the serial ports or USB port. The picture is an example of an external USRobotics modem.
      • Removable modem -
      • Modem used with older laptops PCMCIA slot and can be added or removed as needed.

    • Wi-Fi
    • Wi-Fi is a wireless network that utilizes one of the IEEE 802.11 wireless standards to achieve a wireless connection to a network. A home wireless network uses a wireless access point or router to broadcast a signal using WAP or WEP encryption to send and receive signals from wireless devices on the network. The picture shows a wireless access point with two antennas and an example of how most home users connect to the Internet using a wireless device

    • NIC
    • Short for network interface card, the NIC is also referred to as an Ethernet card and network adapter. A NIC is a computer expansion card for connecting to a network (e.g., home network or Internet) using an Ethernet cable with an RJ-45 connector

    • Smartphone
    • A smartphone is a cell phone that allows you to do more than make phone calls and send text messages. Smartphones can browse the Internet and run software programs like a computer. Smartphones use a touch screen to allow users to interact with them. There are thousands of smartphone apps including games, personal-use, and business-use programs that all run on the phone. The picture is an example of the Apple iPhone, one of the most popular smartphones available today