An automobile model (or car model or model of car, and typically abbreviated to just "model") is a particular brand of vehicle sold under a marque by a manufacturer, usually within a range of models, usually of different sizes or capabilities. From an engineering point of view, a particular car model is usually defined and/or constrained by the use of a particular car chassis/bodywork combination or the same monocoque, although sometimes this is not the case, and the model represents a marketing segment.