What is multi-programming?

Multi programming:

Multiprogramming is the technique of running several programs at a time using timesharing. It allows a computer to do several things at the same time. Multiprogramming creates logical parallelism. The concept of multiprogramming is that the operating system keeps several jobs in memory simultaneously. The operating system selects a job from the job pool and starts executing a job, when that job needs to wait for any i/o operations the CPU is switched to another job. So the main idea here is that the CPU is never idle.

it is very easy way in simple words we can say multiprogramming is the allocation of a computer system and its resources to more than one concurrent application mainframe modernization job or users etc ..