Define what is the difference between an abstract method & virtual method?

Define what is the difference between an abstract method & virtual method?
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Answer :

An Abstract method does not provide an implementation and forces overriding to the deriving class (unless the deriving class also an abstract class), whereas the virtual method has an implementation and leaves an option to override it in the deriving class. Thus Virtual method has an implementation & provides the derived class with the
option of overriding it. The abstract method does not provide implementation & forces the derived class to override the method.
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