This video explains what is abstraction and interface in Java and how to create abstract classes and interface.

0:00 What is abstraction?
1:00 What is an abstraction class
1:09 What is an abstract method
1:51 Implement an abstract class
1:54 Extending an abstract class
2:13 Advantages of abstraction
2:40 What is interface
3:30 Implementing Interface
4:19 Extending an interface
4:50 default method in interface
5:51 Difference between class and interface
6:26 Why do we use interfaces?
6:50 Difference between abstract class and interface
7:23 Difference between interface and multiple inheritance