[JohnRPollard]

In the context you are using them, these terms refer to whether the interior furniture was built up entirely out of wood material (stick built), or was made primarily out of fibreglass (pan interior).

In the case of the pan interior, the general shape of most of the interior furniture is created by the fibrglass pan or pans (often there are several pieces for different sections of the boat). After the pans are dropped into the hull (before the deck is attached), they are then secured in place, and then the pans get trimmed off with varying degrees of wood.

Purists prefer stick-built interiors. The all-wood interior has a very rich feel. Also, on a stick built boat you arguably have better access to the hull in the event of damage, because you can tear/cut the interior woodwork away more easily. A downside to stick-built interiors is that they tend to make a fair bit of creeky/groany noise in a seaway.

Pan interiors reduce costs -- which is the primary reason for their use. They have other advantages in that when properly designed they can be used to greatly stiffen the hull and spread loads. Also, their interior surfaces tend to be less maintenance since they're coated with gelcoat and therefore easy to clean/wipe down.

Most series production boats have pan interiors because they can amortize the expense of investing in the tooling for the pans, and thereby reduce costs. Generally, the very high-end, low volume boats can't do this economically (or choose not to) so are stick built.

Our mid-range boat has a pan interior. It is heavily trimmed out with teak -- many folks don't realize there's a pan until they've been aboard for a while -- some never notice. Also, ours is well designed and permits access to the hull interior virtually everywhere. Our boat is stiff and does not work. I like this arrangment, so I would not necessarily agree that the all wood (stick built) interior is preferable.