The definition of polymorphism is when different types of objects use the method or properties with the same name. Therefore, the programmer doesn't need to know the exact type of an object while coding the application. The precise behavior of a method or property is determined at run-time.

The single sentence definition of polymorphism is"The ability to take more than one form.".

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This is a nice and simple OOP interview question. As the name says POLY (Many) MORPHISM (Change). Polymorphism is the ability of the object to behave differently under different conditions. For instance a simple user object can behave as a admin user or as a simple user depending on conditions.

There are two ways of doing polymorphism dynamic and static. Static polymoprhism is achieved by using method overloading and dynamic polymorphism is acheived by using method overloading. Please note do confuse with overloading and overriding while answering this question. Many .NET developers make a niceversa statement leading to lot of confusion.

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Polymorphism: It's derived from a Greek word, where poly means many morph means Faces/Behaviors.

polymorphism is popularly called as one interface,multiple functions.