Difference Between string and String in C#

Well technically both of these are the same but with a slight difference. While  “string” is a datatype, whereas “String” represents a class. “string” is an alias for System.String. At execution time both are compiled to the same code. One more difference is the syntax highlighter.

Let us now check a code snippet to understand both of these.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            string FirstName = ".Net";
            String Lastname = "Snippets";
            Console.WriteLine(FirstName + " " + Lastname);
            Console.ReadLine();
        }
    }
}

If we hover above string and String we get reference to the same class. Refer to  the screenshots below.

String vs string



string Vs String



So both refer to the same class.