Even though the computer is the heart of any information system, it is dead or useless without software. Software brings life to the computer. Computer  have only two legs : Hardware and Software. Without software, hardware is of no use and without hardware, software is of no use. In the other words we can say that hardware is like an actor and software is like a dialogue or script, or just like a car without fuel.

Software is a set of instructions that tells the computer step-by-step how to perform a particular task. There are two types of software in use : Operating or System software and Application software.

• Operating Software : It tells the computer how to use its own components. It is a set of permanent instructions for getting the compter started. It allows the computer to identify the devices attached to it, memory available etc. before the actual work is starts.     Ex. Microsoft Windows, Unix, Linux etc.

• Application Software : It is a software which makes the computer useful for the people. The programs which help people to do specific tasks are known as 'Application Software'. These softwares have been written to do almost every imaginable task.     Ex. MS Office, Photoshop etc.