A ceiling's an overhead interior surface that bounds the upper limit of a room. It's generally not a structural element, but a finished surface concealing the underside of the floor or roof structure above. A cathedral ceiling's any tall ceiling area similar to those in a church. A dropped ceiling's one in which the finished surface's constructed anywhere from a few inches to several feet below the structure above it. This may be done for aesthetic purposes, such as achieving a desirable ceili… (More on Ceiling)