Swaping reference and type in static method

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            List<int> noSwapList = new List<int>() { 1, 2 };

            //Swap value types - no modification to list.
            Swap(noSwapList[0], noSwapList[1]);
            Console.WriteLine("No swap occures");
            PrintList(noSwapList);

            //Swap ref types - modification to list.
            Swap(noSwapList, 0, 1);
            Console.WriteLine("Swap occures");
            PrintList(noSwapList);


        }

        private static void PrintList(List<int> noSwapList)
        {
            Console.WriteLine();
            foreach (var item in noSwapList)
            {
                Console.Write(item + " ");
            }
            Console.WriteLine();
        }

        static void Swap(int a, int b)
        {
            int temp = a;
            a = b;
            b = temp;
        }

        static void Swap(List<int> list, int firstIndex, int secondIndex)
        {
            int temp = list[firstIndex];
            list[firstIndex] = list[secondIndex];
            list[secondIndex] = temp;
        }
    }

}