Answer:   A delegate is a reference type variable that holds the reference to a method. The reference can be changed at runtime.

Delegates are especially used for implementing events and the call-back methods.

Answer:   In .NET Framework delegates provide a late binding mechanism. it means which we create an algorithm where the caller also supplies at least one method that implements part of the algorithm. Consider sorting a list of stars in an astronomy program. we may choose to sort those stars by their distance from the earth, or the magnitude of the star, or their perceived brightness.