1.	Checked exceptions are exceptions that must be 
declared in the throws clause of a method. A checked 
exception indicates an expected problem that can occur 
during normal system operation. Checked exceptions must be 
2.	Unchecked exceptions are exceptions that do not 
need to be declared in a throws clause. An unchecked 
exception indicates an unexpected problem that is probably 
due to a bug in the code. The most common example is a 
NullPointerException.They don't have to be caught or 
declared thrown.
3.	Checked exceptions in Java extend the 
java.lang.Exception class. Unchecked exceptions extend the 
java.lang.RuntimeException.