C# OO - Polymorphism - Virtual and Override

using System;

namespace LearnCS
{
    class Prim
    {
        public virtual void sameMethod()
        {
            Console.WriteLine("sameMethod, Prim Class, Simple Job");
        }
    }

    class Sec : Prim
    {
        public override void sameMethod()
        {
            Console.WriteLine("sameMethod, Sec Class, Complicated Job");
        }

    }

    class Tert : Prim
    {
        public override void sameMethod()
        {
            Console.WriteLine("sameMethod, Tert Class, Defficult Job");
        }
    }
    
    class Program
    {
        static void Main(string[] args)
        {
            Prim p1 = new Prim(); //Something Basic/Simple
            Prim p2 = new Sec(); //Complicated Job
            Prim p3 = new Tert(); //Difficult Job

            p1.sameMethod();
            p2.sameMethod();
            p3.sameMethod();

            Console.ReadLine();
        }
    }
}