What is a Computer









What is a Computer?



A Computer is an electronic device for storing and processing data.



It uses 0 and 1 - binary method to process data



It takes input from the user through input devices like Mouse, Keyboard, etc and executes the programmed codes or instructions.



The result is displayed in the Monitor screen








What is Operating System

OS - Operating System

An Operating System is a software program that interacts between user and computer hardware.
  • It gets input from users through Keyboard, Mouse and other input devices
  • Converts it to machine readable form in 0 and 1 's with the help of processors which process the entered data
  • Sends the processed data or information to output device like monitor
OS is installed in Internal storage devices like hard disk.


File:Operating system placement.svg  This Image displays the User interaction or instruction from input devices (keyboard or mouse) which is sent to Application layer which is part of OS. 

OS executes the instructions as per the programmed codes or instructions with the help of processor and motherboard functions and returns the processed information back to OS. 

OS in turn displays the result though output device Monitor, to the user .

Examples of Operating Systems:
  • DOS - disk operating system
  • Windows XP, Windows 7, Windows 8
  • Server 2003, Server 2008, Server 2012
  • Linux, Unix, Solaris, Mac


Free Operating System

There are Operating Systems (OS) available in market with Linux / Unix Flavours.

There are also servers available for free.

Free Desktop OS:

Ubuntu - http://www.ubuntu.com/desktop

Debain - http://www.debian.org/

Free Server OS:

Ubuntu - http://www.ubuntu.com/server

Smart Phone / Tablet:

Ubuntu - http://www.ubuntu.com/phone        http://www.ubuntu.com/tablet

Android - http://www.android.com/