This is equivalent to the main() function of regular C.

int
WINAPI
WinMain(
	HINSTANCE hInstance,
	HINSTANCE hPrevInstance,
	LPSTR lpCmdLine,
	int nShowCmd
);
  1. Handle to program executable. Instance Handle
  2. Obsolete feature. Always NULL now.
  3. command line arguments When the program is run, windows automatically passes parameters in so that you have values.