Jukebox:-

 A high-capacity storage device that uses an auto-changer mechanism to mount or dismount optical disks automatically. A jukebox typically contains one to four disks and a mechanism that picks up disks from a bay and loads them into the drives as they are needed.

Jumper:-

A small plastic and metal connector that completes a circuit, usually to select one option from a set of several user-definable options. Jumpers are often used to select one particular hardware configuration from a choice of configurations.