What data type does HWND type belong to?

Question

I'm trying to learn about the Win32api for Ruby, and I've come across the HWND type in different functions such as the MessageBox function. What does the HWND type do, and what data type does it belong to; pointer, integer, or long?

Answer 1

HWND represents a window to the operating system and is an opaque pointer value. That is you may know the value of a particular HWND but you know nothing about the data backing that value.