Was ist das Proxy-Entwurfsmuster und wie implementiert man es in C#?

internal class Program {
   private static void Main(string[] args) {

      NewServerProxy proxy = new NewServerProxy();
      Console.WriteLine("What would you like to order? ");
      string order = Console.ReadLine();
      proxy.TakeOrder(order);

      Console.WriteLine("Sure thing! Here's your " + proxy.DeliverOrder() + ".");
      Console.WriteLine("How would you like to pay?");
      string payment = Console.ReadLine();
      proxy.Processpayment(payment);

      Console.ReadKey();
   }
}

public interface IServerP {
   void TakeOrder(string order);
   string DeliverOrder();
   void Processpayment(string payment);
}
public class ServerP : IServerP {
   private string Order;
   public string DeliverOrder() {
      return Order;
   }

   public void Processpayment(string payment){
      Console.WriteLine("Server Processes the payment " + payment);
   }
   public void TakeOrder(string order) {
      Console.WriteLine("Server takes order " + order);
      Order = order;
   }
}
public class NewServerProxy : IServerP {
   private string Order;
   ServerP _server = new ServerP();
   public string DeliverOrder() {
      return Order;
   }
   public void Processpayment(string payment) {
      _server.Processpayment(payment);
   }
   public void TakeOrder(string order) {
      Console.WriteLine("Server takes order " + order);
      Order = order;
   }
}