If you are a candidate for a design role, or a position where Computer Aided Design (CAD) software will be used, you may be asked about your experience working with different modeling methods. Surface modeling and solid modeling are two different techniques used in CAD work, with the difference being whether or not you are creating surfaces or solids. Surfaces have no thickness, and were developed for the automotive and aerospace industries for contoured parts such as turbine blades and car bodies. Solid models have a thickness to them, and they are used for general manufacturing of parts like engine blocks, machine shafts and gears. When these methods are used together, they are known as hybrid modeling; they can be used to create intricate parts with the added capabilities of surface modeling.