Abstract class may have concrete methods which need not require to be overridden but In Interface all methods need to be overridden .

Abstrct classes are Extended but interfaces are implemented .

in an interface all the methods are by default Abstract.

In Abstract class we can have non-abstract methods.Atleast one method should be abstract others may be abstract or concrete.

Where as i Interface we dont have non-abstract methods.

In abstract classes we use the keyword abstract for the methods where as in interfaces we dont use any such keyword.

Using interfaces the concept of multiple inheritance is acheived but this can not be done with abstract classes.

hi

Diff b/w abstract class and interface are..

Abstract class can have concrete methods also..eventhough if the class doesn't contain any abstract method we can declare that class as an Abstract class.

In case of Interface by default methods are abstract and public only. In the interface also there is a possibility of defining concrete methods using the InnerClasses concept..