Introduction to Windows Operating System

Introduction
A computer is a complex system consisting of both hardware and software components (information stored on hardware). In general the word hardware is used for physical devices such as TV sets, DVD players , computers and others, the word software is used for the information used with such devices: movies, music, novels, web pages, computer programs, and data. When talking about computer systems, hardware means the physical parts of the computer (electronic and mechanical parts), software means the programs and data used with the physical computer.
The major hardware components of a computer system are:
• Processor
• Main memory
• Secondary storage
• Input devices
• Output devices
Many of the components of computer are connected to the main circuit board of the computer, called the motherboard.
The terms input and output say if data flow into or out of the computer. The picture shows the major hardware components of a computer system. The arrows show the direction of data flow.

A bus is a group of wires on the main circuit board of the computer. It is a pathway for data flowing between components. Most devices are connected to the bus through a controller which coordinates the activities of the device with the bus.