What is the difference between sleep() and wait()?

Sleeping is used to delay execution for a period of time, and no locks are
released when a thread goes to sleep.
A sleeping thread is guaranteed to sleep for at least the time specified in
the argument to the sleep() method (unless it's interrupted), but there is
no guarantee as to when the newly awakened thread will actually return to
running.
Sleep method is in java.lang.Thread.