Introduction To Computers


Hello Reader As we are just beginning with Computer knowledge in this Very first Topic of Computer Fundamental, We should know What is Computer Actually, hundreds of time in our day to day life we are using this word.

So Let’s First have the Very Basic Definition of Computer. Ask yourself a Question What is Computer?

Computer is the Electronic Machine which can Take Data as a Input Via Some Inpute Device from the User via  KeyBoard and Process the Data or Information it Received via Input,Perfom Some Required Operation ie it process the data  and Produce the Results that we can see via output Device like Monitor.

Now Let’s Understand the Very Basic Term Data and information that we many times use as we go further into more details.

What is Data?

Any Thing Which is not completely Processed, so it is the groups of Unprocessed facts Numbers Characters Etc.

Eg. 120, Rose ,College ,Syllabus ,Computer Science  etc

Whats is Information?

Information is something which is meaningful ,Usable and organized

For Example :Examradar has Computer Science Syllabus with easy explanations.

So Now here we can Give formal Definition of computer

A computer can be defined as an advanced electronic device that takes raw data as input from the user. It uses a set of instructions (called program) to process the data and give the result (output). The result can be used immediately or saved for future use.

Computer is Consisting of Hardware and Software

Hardware is any part of Computer that we can See, Touch.

Software is the instructions set that order the computer how to Process the Data  and perform the task.

There are Various Components of Computer Hardware ,Which are as Given Below

  1. Input Device
  2. Output Device
  3. A System Unit
  4. Storage Device
  5. Communication Device

Now let’s discuss each one by one and Their Uses

Input devices
input devices are the devices by which a user enter data and instructions into a computer such as keyboard, mouse, microphone etc

Functions of Input Device

  1. Accept Information or Data from the user
  2. Convert the instruction from human readable form to machine Readable form
  3. send information to CPU for further Processing.

Example of input Device:mouse ,keyboard,microphone,scanner,Trackball,JoyStick,Graphics Tablet, Digital Camera etc

Output devices
Output devices are used to display the result or information to the user through monitor printers, plotters and speakers.

Functions of Output Device
It Accepts the Result which is in Machine Readable formate and Conver it into human Readable formate and Supply the Results to User
Example of Ouput Device: Monitor ,Printer,Plotter,Speaker.

Storage devices
storage devices are the devices which are used to retrieved and save the data and information.
Some Examples are Given as below with some details that is enough to understand about each device

  1. Floppy disks: A floppy disk is made up of a circular thin plastic jacket coated with magnetic material, It can hold 1.44
    MB data.
  1. hard disk: is made up of a metal disk and coated with a metal oxide used to store bulk of data.
  1. Compact disk – read only Memory/ CD-ROM: it is read only or read-write disk.It is Fast to Access but Access time longer then that of magnetic disc.
    Following is the Type of CDs
    CD-R-It Stands for  Compact Disk
    It Only Store Data One time,once data is stored it can not be changed
    CD-RW stands for Compact Disk – ReWriteable
    It Can be used to can read, write and erase data as many times.
  1. dvd- Stands for Digital Versatile Disk, optical storage disc, double sided with dual layer disc,Capacity 4.7 GB of data
  2. blue-ray disks
    It is used for  storing more than 25 GB of data with a very high speed in less amount of time
  1. usb stands for Universal Serial Bus. It is a portable memory device which is used to store data ,
    it uses USB port of the system to transfer data.
  2. Memory Card or flash memory card is a memory device, It is an easy, fast and reliable medium , it store and transfer data from one device to the other. Used in digital cameras, game consoles, mobile phones etc.

CPU (Central Processing unit)
CPU is the Main Cabinet Box that Consists of Central Processing Unit(CPU) and Memory
CPU Process we can Say interprets and Executes the Given Instructions
Memory is Where the Instructions and Data were Stored.

CPU is the Heart of Computer System ,Its Consists of ALU (arithmetic and logic unit) Which do Perform all the Arithmatic and Logical Operations . And The Control unit  Which send the Controlling Signal to all other units of Computer System

As we have Already discussed ,Memory Store the data and information.
There are two types of Memory
primary memory and secondary memory or external memory

  1. Primary Memory: It is Very Fast Memory, CPU executes Program instruction and fetch Data from the Primary memory.
    There are two type of Primary Memory
    Random access Memory
    It refers to memory that can be selected and used randomly.
    It is Volatile in Nature that is When you power off or Shutt Down your System ,Data Stored in it will be Erased or Deleted.
    Read only Memory: As the name suggest it is Read only memory ,the data stored in it is Non-volatile ,Data Stored in it at the time of Manufacturing the machine. When we Turn On the Computer Instruction which stored in it Tell the Computer how to Work and Follow the series of Steps before we actually use the computer.
  2. secondary Memory or auxiliary Memory
    well As we know the Content Writtern on RAM Erased when we Turn off the Computer,So it is necessary to             write data somewhere for future use before we switch of the system, So it is the Secondary memory where we        can store data permanently for future use and it is cheaper than Primary Memory.
    Example-Our Hard Disk is Sec Memory.

Units of Memory
Computers work in the base 2 system, also called binary number system ie it understand only 0 and 1. Single unit is Bit
Sequence of 8 Bits makes one Byte
Lets Go in more Details about it.

1 byte = 8 bits

1 nibble = 4 bits

1 Kb = 1024 bytes

1 Mb = 1024 Kb

1 gb = 1024 Mb

1 tb = 1024 gb

1 Pb = 1024 tb

Terms Kilobyte (KB), megabyte (MB), gigabyte (GB), terabyte (TB) and Petabyte (PB) are used.

UpTill now We have Discussed the Hardware now lets Discuss about the Softeware

Computer Hardware do set of operation and the set of instructions which tells the hardware about what to do next. These Set of Instructions is know as Programms and collection of programs makes the complete Software.

There Two Types of Software as Described Below

1 application software

It direct the computer to carry out specific tasks.Multiple programs are joined together to create Application software

For example Word Processors are used such as to write the document.

Spreadsheets are used such as Spreadsheet for calculation etc

2 System software

System software is the interface between user and the application software  and the computer’s hardware.

there are two categories of system software

The operating system

It is a collections of  programs that manages all the other programs on your computer, stores files in an organized manner. It makes coordination between the computer hardware such as the keyboard and mouse.

utility software is a type of system software. It is used to analyze, configure, optimize or maintain the computer. This software performs all the housekeeping work

Below is the type of Utilities Software

  1. Text editors.writing editing documents
  2. Compression utilities:for compressing the files
  3. Disk Fragmentation;this utility software is used to Free space on the harddisk and to arrange the used space and free space which increases the processing speed of computer
  4. Scan disk; this utility software checks the Bad sectors and viruses on the hard disk
  5. Encryption or decryption: utility is used to hide the data for secured transmission,Data is encrypted at the source and it decrypted at the destination before actual use.It requires a secret key or password for

Computers Characteristics

  1. Speed
  2. Accuracy
  3. data storage

Generations of Computers
 Computers have been categorised into five generations on the basis the development of technologies used to manufacture the processors, memories and I/O units

First generation (1945 – 55)-

    1. Bulky, vacuum based ,costly
    2. assembly language which was translated to machine level language for execution
    3. Mainly used for scientific calculations


Second generation (1955 – 65)

  1. Smaller than vacuum based computers
  2. Transistors is used instead of vacuum tube
  3. High level languages like FORTRAN and COBOL were used
  4. Examples: IBM 7030, Honeywell 400

Third generation (1955 – 65)

    1. Small Scale Integration and Medium Scale Integration technology were Used
    2. Faster Processing Speed
    3. This is the time when microprogramming was introduced as were operating system software. Database
      management, multi-user application were introduced

Examples: System 360 Mainframe from IBM, PDP-8 Mini Computer from Digital Equipment Corporation.

Fouth generation (1975 – 89)

    1. Microprocessors were comes in picture now where complete processors and large section of main memory could be integrated into a single chip.
    2. CRT screen, laser & ink jet printers, scanners etc. were developed and so were LAN and WANS. C and UNIX were used

Examples: Intel’s 8088,80286 etc

Fifth generation: 1989 to present

    1. Now Computers use extensive parallel processing, multiple pipelines, multiple processors etc
    2. Portable notebook computers comes into play
    3. object oriented languages such as JAVA comes into picture now I mean start using

Examples: IBM notebooks, Pentium PCs-Pentium 1/2/3/4/Dual core/Quad core. SUN work stations, Origin 2000, PARAM 10000, IBM SP/2.

We will continue our study on fundamental of computer in the next slide, in that we will go through Categories of Computers depending upon their size, functioning and processing capabilities. thats it for Today .

have a good day!