A keychain, or keyring, is a small chain, usually made from metal or plastic, that connects a small item to a keyring. The length of a keychain allows an item to be used more easily than if connected directly to a keyring A keychain, or keyring, is a small chain, usually made from metal or plastic, that connects a small item to a keyring. The length of a keychain allows an item to be used more easily than if connected directly to a keyring.