Division of guitars by material which are made of
If we talk about the wood from which the body (corpus) of the instrument is made, we use the terms massive , semi-solid and plywood.
If we say about the guitar that it is massive, it means that the whole body was made of one piece of wood.
At least some part of the body (front plate, back plate, ...) was made of one piece of wood.
Mostly several layers of wood (or laminate boards) are glued together.