In preemptive scheduling, the highest priority task executes until it enters the waiting or dead states or a higher priority task comes into existence.

In time slicing, a task executes for a predefined slice of time and then reenters the pool of ready tasks.

The scheduler then determines which task should execute next, based on priority and other factors.

Briefly explain daemon thread.

Daemon thread is a low priority thread which runs in the background performs garbage collection operation for the java runtime system.