D irectX is a series of Microsoft technologies providing a consistent, hardware independent multimedia feature set. Most multimedia hardware supports DirectX with optimized drivers, resulting in extremely good performance for applications supporting the DirectX APIs. DirectX 5.0 includes support for Direct3D, DirectDraw, DirectInput, DirectPlay and DirectSound. W in32 is a Microsoft application format for Windows 95 and Windows NT 4.0. This is relevant to 3D games in that most 3D games are true 32-bit applications, which can run comfortably on Windows '95 and Windows NT 4.0.
Alpha blending is a technique which provides for transparent objects.
A 3D object on your screen normally has red, green and blue values for each pixel. If the 3D environment allows for an alpha value for each pixel, it is said to have an alpha channel. The alpha value specifies the transparency of the pixel. These methods are employed in texture mapping. Depth cueing is reducing an object's color and intensity as a function of its distance from the observer.