In general we human beings always know about inheritance. In programming it is almost the same. When a class inherits another class it inherits all features(like variables and methods) of the parent class. This helps in reusing codes.

In the next example we first create a class called Person and create two sub-classes Student and Teacher. As both of the classes are inherited from Person class they will have all methods of Person and will have new methods and variables for their own purpose.