Craft
A craft, vessel or vehicle is a group of parts which is controlled by a command module. A craft may be manned and can be categorized as a rocket, launching vertically usually on the launch pad, or as a plane starting horizontally usually on the runway. Rovers are usually not build to fly or orbit but instead solely cruise on the surface.
Then there are spaceplanes, which are planes which can achieve an orbit. Some rockets and most spaceplanes can reach orbit without dropping anything and are called single-stage-to-orbit (SSTO). Craft can also consists of multiple different craft. Rockets are usually divided into a launcher and payload segment.
Vehicles which aren't controllable anymore are usually called debris and as long as they don't enter an atmosphere can stay for long time in orbit or even forever.
There are various craft already build by the developers called stock craft.
See also
- API:Vessel, the API for craft