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.
Originally, suitcases were made of wool or linen. Leather also became a popular material for suitcases. It was used to cover wood suitcases or just on its own for collapsible suitcases. It is difficult to document all the materials suitcases have been made out of. Like all produced consumer goods the materials chosen to construct suitcases are truly a product of their time. Wool, wood, leather, metal, plastic, fiber composite even recycled materials are all common suitcase materials. During covered wagon times trunks were a popular form of transporting goods. The ride was rough, so the luggage had to be strong. The theme of suitcases becoming less cumbersome over time could be directly related to the advancement of better transportation.
The most sturdy suitcases are generally constructed from wood or polymers and have a covering that resists gouging and liquid from entering into the interior. The seams can be glued together or stitched with strong nylon thread. Generally the stitched-together suitcases hold up over time as compared to the glued construction and have a lock or latch.
Many modern suitcases have built-in small wheels enabling them to be pulled along on hard flat surfaces by a fixed or extendable handle or by a retractable or stowable leash. Suitcases are a type of luggage.
A smaller, firmer suitcase, used mainly for transporting papers and office supplies is known as a briefcase.
Some suitcases that include a telescopic handle and wheels are known as trolley cases (UK) or a roll along (US). Trolley cases/roll alongs typically have two fixed wheels on one end with the handle located on the opposite for vertical movement.