Using New Keyword

Question

Hi guys can any one explain me the functionality of using of New Keyword.Because i worked on that and in the below code i got some doubt i.e., even though i remove the new keyword i was getting the same Output. so what is the use of it.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Base
    {
        public void Display()
        {
            Console.WriteLine("Base Class");
        }
    }
    class derived : Base
    {
        public new  void Display()
    {
        Console.WriteLine("Derived Class");
    }
    }
    class Program
    {
        static void Main(string[] args)
        {
            derived d = new derived();
            d.Display();
            Console.ReadLine();
        }
    }
}