Adapter

An adapter is a device, component, or software module that enables compatibility between otherwise incompatible systems, interfaces, or formats by translating signals, data, or commands.

In hardware, adapters come in several forms. Power adapters convert household AC into the DC voltages used by electronic devices; travel adapters allow plugs from one region to fit sockets in another, though they do not change voltage. Some power adapters also function as voltage converters to match different electrical systems; others merely reshape physical connectors. Cable adapters and dongles can convert between connector types, such as USB-C to USB-A, HDMI to DisplayPort, or Ethernet to fiber.

In information technology, adapters extend or harmonize interfaces. Network adapters enable devices to connect to networks, while USB and PCIe adapters add or change port types. Display adapters convert video signals, for example from HDMI or DisplayPort to VGA or DVI.

In software engineering, the adapter pattern provides a way for classes with incompatible interfaces to work together by wrapping the target interface with a compatibility layer. An adapter translates calls or data from a client to a form understood by a legacy or third-party component.

Considerations include electrical standards, connector compatibility, data rates, and safety. Using an adapter outside its intended use can damage devices or breach warranties, so users should verify specifications and certifications.