Dropped ceiling is a secondary ceiling, hung below the main (structural) ceiling. It may also be referred to as T-bar ceiling, false ceiling, suspended ceiling, grid ceiling, drop in ceiling, drop out ceiling and is a staple of modern construction and architecture in both residential and commercial applications.
What is a ceiling?
A ceiling is an overhead interior surface that covers the upper limits of a room.
It is not generally considered a structural element, but a finished surface concealing the underside of the roof structure or the floor of a story above.
L-Box false ceiling is designed mainly for holding lights without exposing any wiring, to give an elegant design towards the ceiling.
A cornice is generally any horizontal decorative moulding that crowns a building or furniture element— the cornice over a door or window for instance, or along the top of an interior wall. A simple cornice may be formed just with a crown moulding.