Tracks are known as Courses in internal GT terms.
These terms mostly apply starting from Gran Turismo 4.
Course Pack: The course pack contains most of the components that makes up a track. The runway, main model set, model set for the rear-view, camera component, vision list and more.
EnvPtr: Environment parameter. Sets up how a course behaves to lighting, and setups weather parameters.
Gadget: Represents a dynamic object on a course - for example: a cone.
Permanent: Refers to a fantasy track, a track that is permanent. This term is mostly used starting GT Sport but applies in older games aswell.
Rail: Refers to the road aspect of a course in the context of course generation.
Runway: Runways are the collision component of the course. It contains the checkpoints, boundaries, collision tree, starting grid points and more.
Scenery: Refers to the background aspect of a course.
VCoord: Represents one meter progression on the track. i.e VCoord
2000would be half way through High Speed Ring (which is 4.000 meters).
Vision List: Vision lists (also known as VLS) determine what models should rendered on a precise point on the track.