what are the Differences between Abstract Class and Interface ?

Sno	Abstract Class	Interface
1	Can have implemented Methods	Cant
2	A class can inherit only one abstract class	A Class can implement any number of Interfaces.
3	We go for Abstract classes on such situations where we need to give common functionality for group of related classes	We go for Interface on such situations where we need to give common functionality for group of un-related classes
4	If you add a new method, then you can provide a default implementation and so no need to make any change to existing work.	If you add a new method, then you need to change all the existing work.
5	Static and Instance constants are possible.	Only Static constants are possible.