The light type property defines which type of Direct3D light object you're using. The light type is set by using a value from the D3DLIGHTTYPE enumeration in the dltType member of the light's D3DLIGHT2 structure. There are four types of lights in Direct3D Immediate Mode—point lights, spot lights, directional lights, and parallel-point lights. Each type illuminates objects in a scene differently, with varying levels of computational overhead. For general information about how each type of light works, see Introduction to Light Objects.