VO
Generated
Automatically-generated texture coordinates from the vertex positions of the mesh without deformation, keeping them sticking to the surface under animation. Range from 0.0 to 1.0 over the bounding box of the undeformed mesh. See Texture Spaces for more information.
Object
Uses an object as a source for coordinates. Often used with an empty, this is an easy way to place a small image at a given point on the object. This object can also be animated, to move a texture around or through a surface.