The term “Interior” (abbreviated Int.) refers to any Location for a Scene that takes place within a covered building.
There may be some portals (such as windows or doors) through with some amount of Exterior scenery or lighting may be visible, but as long as the principal actors are operating from the interior of the building, it is still considered an Interior Location.
See also: Exterior
Note: Although this term is most frequently used (as here) when describing the Location of a Scene, the Game Engine also differentiates between Interior and External Camera Angles as well. Usually a matching type of Camera Angle is used for a particular Scene, but it is technically possible to have an Interior Scene going on and to show it (or even just one shot of it) from an Exterior Camera Angle that has a vantage point that is looking in on that action, or vice versa.