Walls and Ceilings
What is the basic composition of a room of a building? Imagine if you were inside a room (of any kind of building). Since you can generally think of a room cubical, rectangular, or perhaps cylindrical (if the architect designed it that way) then a building (since buildings are made of rooms) in a basic sense is just a combination of a series of walls, and a ceiling. Take away one, then the building would not look like the conventional vision or description stored in our memory.
Ceiling
Walls and ceilings since are one of the most important parts of a building (but then again, what part of a typical building is not important? Every part has of course a purpose to play, but focusing on ceilings and walls, which are the parts of a building that our eyes often rest upon…) cannot be denied even at the slightest difference of the attention both require from the builders if a building is to be at its best.
Glass House Ceiling
Ceiling is the upper interior surface facing down just below a roof or the next floor of a building. Although a building does not need a ceiling for it to exist in terms of structural reasons, it would not look as good if it had a finished surface at its upper limit.
In an absolute sense, the ceiling is used for decorative purposes, thus it provides an excellent way to apply the theme of a room or building into it making the structure more appealing.
One famous ceiling is located at the Sistine Chapel of Vatican city, which has priceless paintings made by the great painter Michelangelo.
For a list of all the types of ceilings check out this article – Ceiling from Wikipedia.org.