Sealed method in C#

Question

I am a newbie in C#.I am reading about Sealed keyword.I have got about sealed class.I have read a line about Sealed method where we can make Sealed method also.The line was

Answer 1

Sealed Methods

Sealed method is used to define the overriding level of a virtual method.

Sealed keyword is always used with override keyword.

Practical demonstration of sealed method

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

namespace sealed_method
{
    class Program
    {
        public class BaseClass
        {

            public virtual void Display()
            {
                Console.WriteLine("Virtual method");
            }
        }

       public class DerivedClass : BaseClass
        {
            // Now the display method have been sealed and can;t be overridden
            public override sealed void Display()
            {
                Console.WriteLine("Sealed method");
            }
        }

       //public class ThirdClass : DerivedClass
       //{

       //    public override void Display()
       //    {
       //        Console.WriteLine("Here we try again to override display method which is not possible and will give error");
       //    }
       //}

        static void Main(string[] args)
        {

            DerivedClass ob1 = new DerivedClass();
            ob1.Display();

            Console.ReadLine();
        }
    }
}