[Oracle interview]What is the difference between preemptive scheduling and time slicing?

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