A suitcase is a general term for a distinguishable form of luggage. It is often a somewhat flat, rectangular-shaped bag with rounded/square corners, either metal, hard plastic or made of cloth, vinyl or leather that more or less retains its shape. It has a carrying handle on one side and is used mainly for transporting clothes and other possessions during trips. It opens on hinges like a door. Suitcases lock with keys or a combination.