changer

A changer is a device or mechanism that automatically changes, selects, or arranges among a set of items or states. The term is used across domains to describe equipment that moves from one item to another with minimal or no user intervention, such as switching between media, currencies, or data storage media.

In media playback, changers include record changers and CD changers. An automatic record changer stores multiple vinyl records and can switch between discs without manual handling. CD changers hold several discs and switch playback to a chosen disc or a queued sequence, a form common on home stereos and early car audio systems.

In commerce and service machinery, a coin changer (or money changer) accepts currency and dispenses change, typically integrated into vending machines, ticketing kiosks, and arcade games. Some devices also incorporate bill validators or note changers to handle paper currency.

In data storage and automation, a changer refers to an automated media handler that feeds removable media into drives. Examples include tape library changers, optical disc changers, and other multi-media changers used in data centers and archival systems to manage large stacks of storage media with robotic or mechanical selection.

In software and user interfaces, the term changer can describe components that swap content or views, such as a page changer or content changer in applications and web interfaces. These implementations automate transitions between different screens, datasets, or visual states.

Etymology traces changer to the French changer, meaning to change, with usage in English dating back several centuries.