operatpor overloading in c++

i was trying exercise on programmr.com. but i didn't get below example of basic operator overloading. can somebody please explain me below. challenge is:- "Overload the + operator for the class 'temp' to add and return the answer of two objects of class 'temp'."

   #include <iostream>

using namespace std;

class temp
{
  int value;

public:
  temp(int v=0) : value(v) { }

  //WRITE YOUR CODE HERE



  //

  int getVal()
  {
      return value;
  }
};

int main()
{
    int n1, n2;
    cout << "Enter value for t1: ";
    cin >> n1;
    cout << "Enter value for t2: ";
    cin >> n2;
    temp t1(n1), t2(n2), t3;
    t3 = t1+t2;
    cout << "Their sum is " << t3.getVal();
    return 0;
    }