Apa WinAPI itu?

Windows.h is the main header file for WinAPI.

WinAPI is anything and everything related to programming on Windows. Anything that involves window creation/management or communication with the OS or filesystem.

Things like:
- Creating Windows
- Basic graphical capabilities (WinGDI)
- Enumerating files in a directory
- Popping up common dialog boxes ("Save As" dialog, "Pick a color" dialog, etc)
- Querying information about the system (like running processes, etc)
- etc
- etc

The list goes on and on. WinAPI is huge.

Kalau mau dipakai di deklarasikan dulu.