Windows API

The Windows application programming interface (API) is the system programming interface to the Microsoft Windows operating system family, including Windows 2000, Windows XP, Windows Server 2003, Windows 95, Windows 98, Windows Millennium Edition (Me), and Windows CE. Each operating system implements a different subset of the Windows API.

Prior to the introduction of 64-bit versions of Windows XP and Windows Server 2003, the programming interface to the 32-bit version of the Windows operating systems was called the Win32 API, to distinguish it from the original 16-bit Windows API, which was the programming interface to the original 16-bit versions of Windows.

The Windows API consists of thousands of callable functions, which are divided into the following major categories:

• Base Services

• Component Services

• User Interface Services

• Graphics and Multimedia Services

• Messaging and Collaboration

• Networking

• Web Services