What exactly is a keychain? you ask.
Well a keychain or key chain is a small chain, usually made from metal or plastic that connects a small item to a keyring. A keychain is also known as a key fob. The length of a keychain allows an item to be used more easily than if connected directly to a keyring. Some keychains allow one or both ends the ability to rotate, keeping the keychain from becoming twisted, while the item is being used. A key chain can also be a connecting link between a keyring (a.k.a. "split ring") and the belt of an individual. It is usually employed by personnel whose job demands frequent use of keys, such as a security guard, prison officer, janitor, or retail store manager. The chain ensures that the keys remain attached to the individual using them, makes accidental loss less likely, and saves on wear and tear on the pockets of the user. A keychain can also be a short chain used to link together a number of keys or other items. Sometimes keychains are even hung on walls.