Exception is an abnormal condition that arises in the program during execution. When such a condition arises in the program, an appropriate code is written so that it can be handled.

By using the exception handling you can prevent your program from abruptly ending, flashing surprisinly and annoying error messages. On the contrary, if a minor error crops up it can be handled during runtime and your program resumes from there on without crashing down.

 All exceptions in Java are subclasses of the built-in-class called 
Throwable. There are two main subclasses under throwable: Exception and 
Error.