When a class is not used for creating objects, it is called an abstract class. The abstract class
can act as a base class only. It is a layout abstraction in a program, and it allows a base on which
several levels of inheritance can be created. The base classes act as a foundation of the hierarchi-
cal class. An abstract class is developed only to act as a base class and to inherit, and no objects of
this class are declared. An abstract class gives a skeleton or a structure; using this, other classes are
shaped. The abstract class is central and generally present at the starting
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