Class

Abstract Class
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Here inheritance is possible, instantiating object is not possible
The Abstract class Abstract method will be implement only in derived class by OVERRIDE.
At least one Abstract method is must and should in Abstract Class.



Interface
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It’s a pure abstract class.
It has only Abstract methods no implementation. Implement methods through class.

Can inherit can’t create object to interface.

Public Access modifier not private

It’s a indicator. It indicates what, class must provide after inherited the interface. OVERRIDE no need.

Multiple inheritance is possible through Interface only in C#.