C# - Internal Keyword

Internal Keyword

Any member with internal access specifier can be accessed from any class or method defined within the application in which the member is defined.

using System;
 
namespace RectangleApplication
{
    class Rectangle
    {
 
        internal double length;
        internal double width;
 
        double GetArea()
        {
            return length * width;
        }
 
        public void Display()
        {
            Console.WriteLine("Length: {0}", length);
            Console.WriteLine("Width: {0}", width);
            Console.WriteLine("Area: {0}", GetArea());
        }
    }
 
    class Demo
    {
        static void Main(string[] args)
        {
            Rectangle rc = new Rectangle();
            rc.length = 10.35;
            rc.width = 8.3;
            rc.Display();
            Console.ReadLine();
        }
    }
}