Why we use Abstract classes? or need of Abtract class

We cannot create the object of abstract class but we can inherit it.

Abstract classes have the following features: (According to MSDN)

• An abstract class cannot be instantiated.

• An abstract class may contain abstract methods and accessors.

• It is not possible to modify an abstract class with the modifier because the two modifers have opposite meanings. The sealed modifier prevents a class from being inherited and the abstract modifier requires a class to be inherited.

• A non-abstract class derived from an abstract class must include actual implementations of all inherited abstract methods and accessors.