When a computer is operated by a user, Operating system monitors all mouse, keyboard and other actions like playing music. Although your media player looks like playing music, it's the operating system that plays music. Media Player gives you an interface to the operating system.

What are these Operating Systems?

The operating system (OS) is the first thing loaded onto the computer. Without a operating system, a computer can't be used.

Operating systems run on electronic devices, like mobile phones, Digital TVs, Game Devices and wireless access points.

The purpose of an operating system is to control hardware and software to behave in a predictable way.

When you want to print a document, the operating system takes control.

When you need to scan some paperwork, the operating system handles the request.

The operating system acts as a middleman between the user, and hardware and software.

It decides how to best utilize your computer's limited processing power.

Following are some of O/S Functions

Input and Output (I/O)
O/S helps you interact with your PC through your monitor, keyboard, and mouse without having to worry about the details of those I/O devices.


File Management
O/S allows users to create, save, delete, move, and copy files.

Program Execution
O/S loads your applications like word processing, spreadsheets, database, etc. from the hard drive into RAM.

Starting Up the Operating System
O/S must be stored on your hard drive until they can be loaded into random access memory (RAM). When you turn on your computer, your PC's BIOS (Basic Input Output System) places a small amount of operating system code into RAM. As a result, the reminder of the operating system is loaded into memory.

The Kernel and the Shell
The kernel is the brain of the operating system that deals with computer's hardware. You can interact with Kernal through a shell program.

Start > Run > CMD starts MS DOS Shell
Type dir to get file list
Type help for help

The shell program is used to give commands to the computer. Some operating systems use a command line interface that allows you to type in specific commands. Others have a graphical user interface (GUI). GUIs use windows, menus, and icons to help you control your computer.


Multi-user and Multitasking
Multi-user operating systems are especially proficient at giving employees the ability to share resources such as printers or memory. Today, many operating systems have multitasking capabilities. They can run several programs at once, and monitor each process. A process is a program that is currently running.