What is the difference between Preemptive and non-preemptive scheduling? - Question & Answer Book

 

Answer. Tasks are usually assigned with priorities. At times it is necessary to run a certain task that has a higher priority before another task although it is running. Therefore, the tunning task is interrupted for some time and resumed later when the priority task finished its execution. This is called preemptive scheduling.

Preemptive scheduling: Preemptive scheduling is prioritized. The highest priority process should always be the process that is currently utilized.

Non-Preemptive scheduling: When a process enters the state of running, the state of that process is not deleted from the scheduler until it finishes its service time.