Diff b/w Checked Exception and Un checked exception

Checked Exception : The exceptions which are checked by the compiler so that execution of the program at runtime is very smooth is called Checked Exception.
Unchecked Exception : The exceptions which are unable to check by the compiler
Runtime and its child classes and error and its child classes are called Unchecked Exceptions and remaining are Checked Exceptions.
Note :
1. Either Checked or unchecked exceptions always occured at runtime only.
2. Fully Checked Exception means parent and child classes must be Checked Exceptions otherwise it would be Partially Checked Exception.