What is the difference between preemptive scheduling and time slicing? Preemptive scheduling enables the highest priority task execution until waiting or dead states entered. It also executes, until a higher priority task enters.
Time slicing allows a task to execute for a stipulated time slice and then reenters the pool of ready tasks. At that time the scheduler determines the executable task, based on the priority and various other tasks.
If a certain task is running and the scheduling method used is preemptive, and then if there is another task that has a higher priority than the executing task, then the executing task is preempted by the higher priority task.
In time slicing methods, a task executes for a predefined slice of time.
After the execution of that task, if there is another task with a higher priority, the scheduler executes the priority task the next depending on priority and other factors..