A texture is a rectangular array of colored pixels. You can think of it as a source of texels (texture elements) for the rasterizer. Although the rectangular texture does not necessarily have to be square, the system deals most efficiently with square textures.
You can use textures for texture-mapping faces, in which case their dimensions must be powers of two. If your application uses the RGB color model, you can use 8-, 16-, 24-, and 32-bit textures. If you use the monochromatic (or ramp) color model, however, you can use only 8-bit textures.
This section describes Direct3D textures and the ways your applications can use them.
·Surfaces, Devices, and Handles