• Yield() method causes to pause current thread execution to give the chance for waiting thread of the same priority. 
• If the there is no waiting thread or all waiting threads have low priority, then same thread continue its execution. 
• If multiple threads are waiting with the same priority, then which thread will get the chance. We can’t expect. 
• It depends on thread-scheduler.
• The Thread which is yield, when it will get the chance once again. It depends on Thread-schedular and we can expect exactly. 

Complete prototype:
public static native void Yield(); 
Native methods are not implemented in java. It is implemented in non-java.