Delegates in C# You want to pass a function as a Parameter ? How does C# handles a callback function or an event handler ? The answer of all these questions is one i.e. a Delegate. Delegate is a reference type datatype that defines a method prototype. We can define a varibale of delegate just like any other datatype that can refer to any method with the same prototype i,e, signature. Define a Delegate => Set a Target Method => Invoke eg: public delegate void MyFirstDelegate(string str); // Declaration Note: declaration can be done outside or even inside the class. static void MethodA(string str) { Console.Writeline(str); } //Setting up Target Method 1) MyFirstDelegate del = new MyFirstDelegate(MethodA); 2) MyFirstDelegate del= MethodA; 3) MyFirstDelegate del = (string msg) => Console.Writeline(msg); //Invoke del.Invoke("Hello World!"); del("Hello World");