Q1. What is the difference between yield() and sleep()?
Ans. When a object invokes yield() it returns to ready state. But when an object invokes sleep() method enters to not ready state.
Q2. Explain Thread States ?
Ans. Runnable - waiting for its turn to be picked for execution by the thread schedular based on thread priorities.
Running - The processor is actively executing the thread code. It runs until it becomes blocked, or voluntarily gives up its turn.
Waiting: A thread is in a blocked state while it waits for some external processing such as file I/O to finish.
Sleeping - Java threads are forcibly put to sleep (suspended) with Thread.sleep. they can resume using Thread.resume method.
Blocked on I/O - Will move to runnable after I/O condition like reading bytes of data etc changes.
Blocked on synchronization - Will move to Runnable when a lock is acquired.
Dead - The thread is finished working.