Delegates vs Interfaces in C#

// C# program to illustrate Delegates
using System;

class GFG {

    // Declaring the delegates
    public delegate void AddVal(int x, int y);

    public void SMeth(int x, int y)
    {
        Console.WriteLine("[{0} + {1}] = [{2}]",x,y, x + y);
    }

    // Main Method
    public static void Main(String[] args)
    {

        // Creating the object of GFG class
        GFG o = new GFG();

        // Creating object of delegate
        AddVal obj = new AddVal(o.SMeth);

        // Pass the values to the method
        // Using delegate object
        obj(190, 70);
    }
}

// C# program to illustrate the
// concept of interface
using System;

// A simple interface
interface inter {

    // method having only declaration
    // not definition
    void display();
}

// A class that implements the interface
class Geeks : inter {

    // providing the body part of function
    public void display()
    {
        Console.WriteLine("Welcome to GeeksforGeeks..!");
    }

    // Main Method
    public static void Main(String[] args)
    {

        // Creating object
        Geeks o = new Geeks();

        // calling method
        o.display();
    }
}