Operating System

Operating System is the vital program which runs on the computers. It is a must for today’s general purpose computers to be able to run the other programs. Actually, these are the operating systems who perform the basic tasks like recognizing input commands, sending the output to the display screen and controlling peripheral devices like printers, scanner etc. etc.

For the complex systems, the operating system has to be capable to handle the greater responsibilities. The operating system works like a traffic cop while making sure that different programs and users running at once do not interfere with one another. The operating systems also take care of security while ensuring that unauthorized users may not access the computer system.

Usually the operating system is classified into following categories.

Multi User:
This operating system allows the two or more users to operate programs at the same time. There are may operating systems which even allow hundred and thousands of concurrent users.

Multiprocessing:
Multiprocessing Operating System supports running a program on multiple CPUs.

Multitasking:
Multitasking Enables the more than one program to run concurrently.

Multithreading:
Multithreading enables the different parts of the single program to run concurrently.

Real Time:
Real Time responds to input instantly. The general purpose commonly used operating systems like DOS and UNIX are not real-time.

Operating systems act as a software platform where the other application programs are operated for desired results.

These application programs are written to run on top of a particular operating system. Therefore, our selection of operating system determines greatly the application we can run. For the personal computers, the commonly used operating systems are DOS, OS/2 and Windows.

Being a user, we usually interact with the operating system through a set of commands.

For instance, the DOS operating system comprises commands like COPY and RENAME for copying the files and changing the name of files in respective manner. The command processor in an operating system accepts and executes the commands.

The graphical user interface enables the users to apply the commands while pointing and clicking at the objects which are appearing on the screen.