

yield() method is mainly used to release the lock of resource and pull up in to steady state from wait pool.Usually the JVM uses this call to activate another thread of the same thread priority.
Sleep() will pull the thread to sleep for the given time. It will throws exception while trying to interrupt in b/w the sleep state.sleep(x) tells the JVM Thread Scheduler to actively put this thread to sleep and not run it again until at least x milliseconds have elapsed.