A standardized multiplexing intermediate interface. It does not usually connect directly to a processor or a peripheral, but provides a standardized interface to which a number of peripheral interface adapters and a single computer interface controller can be connected.

The peripheral adapters may each have different functions (e.g. digital to analogue converter, level changers, parallel to serial converter), and thus have different interfaces facing outward from the CAMAC. Similarly the controller module connects to the CAMAC interface but the outward-facing interface can be chosen to suit the available computer. The name CAMAC was chosen to symbolize this characteristic of looking the same from either direction. The adapters are typically a single printed circuit card that plugs into the internal 86-way connector. The outward-facing connections are usually mounted on a panel attached to the circuit card or may be made via a second connector mounted above the 86-way CAMAC connection. The interface is widely used for connecting instruments and transducers to computers.

CAMAC was proposed as a standard by the UK Atomic Energy Authority and further development and documentation was done by the European Standards of Nuclear Electronics (ESONE) and the Nuclear Instrument Module Committee of the US. The parallel interface is documented in IEC-522 and the modular construction is in IEC-516.