using System;

public class Program

{

    public static void Main()

    {

        String      str1 = "abcd";

        String      str2 = "abcd";

        String      str3 = "ABCD";

        Console.WriteLine(str1.Equals(str2)); //True

        Console.WriteLine(str1.Equals(str3)); //False for upper case

        Console.WriteLine(str1.Equals(str3.ToLower())); //True Recommend this because you can compare the user with User and this isn't same.

    }

}