MAU is also sometimes used as the abbreviation for the token ring network multistation access unit (MSAU).
In an Ethernet local area network (LAN), a media attachment unit (MAU - rhymes with COW) is a device that interconnects the attachment unit interface port on an attached host computer to the Ethernet network medium (such as unshielded twisted pair or coaxial cable). The MAU provides the services that correspond to the physical layer of the Open Systems Interconnection (OSI) reference model. It provides an electrical connection and a transceiver that maps the digital bits between the computer and the network and detects collisions and retries transmissions. A MAU can be built into the computer workstation or other device or it can be a separate device.