what its start: mean? Is it a funtion or some thing else?

Question

#include <iostream>

using namespace std;

int
main ()
{
start:
  int namnff = 23;
  cout << "Hello World" << namnff;

  return 0;
}

Answer 1

It's called a 'label'. Yu can refer to it with goto statement. For example: goto start;

One can write labels in front of any statement in a program.