System Engineer

Similar to Default Method in Interface, the static method in an interface can be defined in the interface, but cannot be overridden in Implementation Classes. To use a static method, Interface name should be instantiated with it, as it is a part of the Interface only.

There are two types of polymorphism in Java: compile-time polymorphism and runtime polymorphism. We can perform polymorphism in java by method overloading and method overriding.
If you overload a static method in Java, it is the example of compile time polymorphism.

Runtime polymorphism or Dynamic Method Dispatch is a process in which a call to an overridden method is resolved at runtime rather than compile-time. In this process, an overridden method is called through the reference variable of a superclass. The determination of the method to be called is based on the object being referred to by the reference variable.

1) Abstract class can have abstract and non-abstract methods. Interface can have only abstract methods. Since Java 8, it can have default and static methods also.
 

2) Abstract class doesn't support multiple inheritance. Interface supports multiple inheritance.

3) Abstract class can have final, non-final, static and non-static variables. Interface has only static and final variables.
 

4) Abstract class can provide the implementation of interface. Interface can't provide the implementation of abstract class.
 

5) The abstract keyword is used to declare abstract class. The interface keyword is used to declare interface.
 

6) An abstract class can extend another Java class and implement multiple Java interfaces. An interface can extend another Java interface only.
 

7) An abstract class can be extended using keyword "extends". An interface can be implemented using keyword "implements".