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Fundamentals of Computer


What is a Computer?



Fundamentals of Computer




computer is a machine or device that performs processes, calculations, and operations based on instructions provided by a software or hardware program. It is designed to execute applications and provides a variety of solutions by combining integrated hardware and software components.







Components of Computer:

1. Input Unit:

The information is given to the computer through an input device such as Keyboard, mouse, scanner, etc.
  • It accepts data and instruction from the user
  • It converts the accepted instructions into the machine language
  • It gives converted instruction to the CPU for processing.



Example Keyboard, Mouse, Light pen, Joystick, Magnetic Ball, OCR (Optical character reader), Floppy disk drive, magnetic Disk, Smart Card Reader, Touch Screen, Punched card Reader, Stylus and tablet, Puck of microphone, digital camera, Scanner, etc.   

2. Central processing Unit (CPU)

Processing is the manipulation of information inside the computer in an area called the central processing unit (CPU)

  •  All processing work of computation is performed by the CPU.
  •  It is also termed as the brain of the computer.
  •  It controls all the parts of the computer system


The CPU is further classified into three components.



1.  Arithmetic Logic Unit: The arithmetic logic unit is a part of the execution unit, core components of all the CPUs. ALU performs all arithmetic and logic operations. It consists of a number of small locations, termed as register. It has two parts

·   Arithmetic section: All the complex arithmetic expressions are performed by repetitive combinations of these operations.

·   Logic Section: It performs all logic operations like comparing, selecting and merging data.

2.  Control Unit:  A control unit is a part of the CPU that directs its operation. It gives the command to transfer data from the input devices to memory and from memory to the arithmetic logic unit. It transfers the results from memory to output unit.

3.  Memory: The brain of the Computer. There are two kinds of computer memory:

  •      Primary/ Temporary Memory
  •      Secondary/Permanent Memory


 The memory holds the data received from the input device. It holds the data being processed and intermediate results being generated. It holds the system software and the application system software in use.


RAM (Random Access Memory) - RAM is where all active programs and data are stored so that they are readily available and easily accessed by the CPU.

  •     EDORAM (Extended Data output random access memory)
  •     DRAM (Dynamic Random Access Memory)
  •     SDRAM (Synchronous Dynamic Random Access memory)



ROM (Read Only Memory) - ROM is logical then that data stored in ROM cannot be changed. The ROM is nonvolatile, which means that it can keep its contents even without a power source.

  • PROM (Programmable Read-Only Memory)
  • EPROM (Erasable Programmable Read-only Memory)
  • EEPROM (Electrically Erasable Programmable Read only Memory)
  • CMOS (Complementary Metal-oxide Semiconductor)




Cache Memory- cache memory is accessed much faster than conventional Ram. It is used to store programs or data currently being executed or temporary data frequently used by the CPU.


3. Output Unit: Output is the result of processing. The output may be viewed on a computer monitor, heard through speakers, printed on printers, etc.
  • It accepts processed data from the CPU.
  • It converts the results from machine language into some simple language.
  • It displays results to users.


Example Visual Display Unit, Floppy Disk Drive, Pen drive, Plotters etc.


4. Software: Software is a set of instructions that directs the computer to process information. Computer software can have various functions such as controlling, hardware, performing computations, communications with other software, human interaction, etc.

A Classification into three types:
  • System Software: It synchronizes the operation of the various hardware components of the computer E.g. DOS, UNIX, etc.
  • Application Software: It is a set of programs designed for specific users or application E.g. Microsoft Office (Word, PowerPoint, Excel)
  • Utilities Software: Utility programs are used to debug the errors. Correct data and help to sort data etc. E.g. Antivirus software


5.  Hardware:  Part of a computer that we can feel, touch and work is called hardware of the computer. For instance- Mouse, printer, scanners, keyboard, etc.


6. Firmware: Firmware is the technology that has a combination of both hardware and software. A typical example of Firmware is the BIOS chip (Basic Input Output System) inside a computer. This hardware chip is located on the motherboard and has BIOS setup software stored on it.