Mecha may refer to a science fiction genre that centers on robots or machines controlled by people. These machines vary great in size and shape, but are distinguished from vehicles by their humanoid or biomorphic appearance. Different subgenres exist, with varying connotations of realism. The concept of Super Robot and Real Robot are two such examples found in Japanese anime. The term may also refer to real world piloted humanoid robots / non-humanoid robotic platforms, either currently in existence or still on the drawing board (i.e. at the planning or design stage). Alternatively, in the original Japanese context of the word (see Characteristics), 'mecha' may refer to mobile machinery/vehicles (including aircraft) in general, manned or otherwise.