Is DirectX Direct 3d

I just downloaded DirectX 8.1 and Im gonna start playing around with it. What I want to know is Direct 3D the same thing as DirectX or a part of DirectX? How about DirectSound and DirectPlay, etc. for that matter? Also, What is the purpose of Direct3D, if you already have a 3D graphics program, what do you need direct3D for?

all those direct... are parts of DirectX
Direct 3d is a layer for program to be able to do fast 3d graphics without having to access the Graphicsboard directly.
The layer is very thin though, so it's fast.

Direct3D is simply a part of DirectX. It has been renamed DirectX Graphics for version 8.0 and up.

D3D allows almsot direct access to the video card, as MisanThrop has said. You can then create any type of 3d application that you like.

Z.