Operator Overloading

Question

Hi Dudes

Can any one tell me

and what is the real use of operator overloading and below i have make a program can any one explain it.....?

 

 

using System;
class Training
{
  string course;
  int duration;

  public Training(string course, int duration)
  {
    this.course = course;
    this.duration = duration;
  }
  public static int operator +(Training t1, Training t2)
  {
    return t1.duration - t2.duration;
  }
}

 

class Program
{
  public static void Main()
  {
    Training t1 = new Training("PHP", 4);
    Training t2 = new Training("ASP.NET", 4);
    int total = t1 + t2;
    Console.WriteLine(total);
    Console.ReadKey();
  }
}