Hi, Suppose you are developing important Java class which implements some algorithm. After completion and full testing of the Java class you are planning to release it for other developer.

In case you won't want anyone to modify the data or logic within your class for this you will hide all the functions and variables from external access. This process of hiding/securing the class is know as Abstraction.

Abstraction In Java allows you to hide the class implementation. Check the tutorial Abstraction In Java for examples on Abstraction.

Thanks