int vs IntPtr when you have a handle?

First a background question:

In general, what is the difference between int and IntPtr? My guess is that it is an actual object rather than a value like an int or byte is. Assuming that is true:

So they are not the same. Yet I see handles represented as both.

1. IntPtr: Control.Handle

2. int (or uint): A PInvoke can be setup to return an int and it works just fine:

     [DllImport ("coredll.dll", SetLastError = true)]
   общедоступный статический extern int GetForegroundWindow ();
   частная строка GetActiveWindow ()
   {
    const int nChars = 256;
    int handle = 0;
    StringBuilder Buff = новый StringBuilder (nChars);
   
    handle = CoreDLL.GetForegroundWindow ();
   
    если (CoreDLL.GetWindowText (дескриптор, Buff, nChars)> 0)
    {
    вернуть Buff.ToString ();
    }
   
    возвращение "";
   }
   

Итак, int vs IntPtr ? Имеет ли значение для ручек? Можете ли вы использовать то или иное?