Class

Interface

A class contains the implementations.

An interface contains specifications.

A class can contain the following members:

1. Instance and static variables 

2. Instance and static block 

3. Instance and static methods 

4. Constructor 

5. A class cannot contain an abstract method 

An interface can contain the following members:

1. public static final variables 

2. public abstract methods 

Members of a class can be public, private, protected or default.

All the members of the interface should be public. If no access specifier specified for members then compiler add public access specifier.

We can create objects for class.

class A {

}

class B {

        A a = new A();

}

We cannot create objects for interface.

Class can be extended by class using extends keyword.

Interface can be implemented by class using implements keyword.

Class does not support multiple inheritance. Class can extend only one class.

abstract class A {

}

class B extends A {

}

Interface supports multiple inheritance. Class can implement any number of interfaces.

interface A {

}

interface B {

}

class C implements A, B {

}

It does not support dynamic polymorphism.

It supports dynamic polymorphism.