An asset is something you use it could be a model or it could be an image. So if I'm going to say model a car my assets could be some car blueprints, some textures I'd saved etcetera.
A lot of people just use the word asset to refer to a model.
All the best
David
From a readers' Q and A column in TV GUIDE: "If we get involved in a nuclear war, would the electromagnetic pulses from exploding bombs damage my videotapes?"