Question

What are the set of programs which are used to perform specific types of job

Answer 1

There are two categories of programs. Application programs (usually called just "applications") are programs that people use to get their work done. Computers exist because people want to run these programs. Systems programs keep the hardware and software running together smoothly. The difference between "application program" and "system program" is fuzzy. Often it is more a matter of marketing than of logic.