C# STRING REPLACE CONCEPT

using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace ConsoleApplication17 {     class Program     {         static void Main(string[] args)         {             String input = "Google is good company";             Console.WriteLine("Input Value = " + input);             String output = input.Replace("good", "better");             Console.WriteLine("After reaplce = " + output);             Console.ReadKey();         }     } }