• Revised old :
• In C#, a namespace is a logical container used to organize code elements and prevent naming conflict

• Below was the first Test run "Hello World"
• An internal class is a class whose visibility is restricted to the same assembly
• Please refer : https://www.geeksforgeeks.org/c-sharp/namespaces-c-sharp/ for more clarity on public vs. internal class.

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

namespace ConsoleApp1
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello, World!");
        }
    }
}