A texture in 3D graphics refers to a 2D bitmap image that is used to make objects more than a plain colour. Sometimes people use the term 'texel', which means a texture pixel. This is just a pixel on the texture, as opposed to a pixel that is rendered when the texture is used, which can be scaled and rotated so that the texture is not exactly represented on the screen. The way DirectX determines the colour of a pixel on a texture object is it finds its position relative to the UV co-ordinates on the object, and looks up what texel that pixel is over. Objects can have multiple textures, and when shaders start being used they can be completely changed.