What do you call an opening in the wall or floor?

An opening in the wall or floor is commonly referred to as a "doorway" if it is intended for passage, or a "window" if it is designed to allow light and air. If the opening is for structural purposes, it may be called an "opening" or "aperture." In construction, specific terms like "vent" or "hatch" may also apply depending on the function of the opening.