Ethernet refers to a family of local area network technologies for connecting devices on a network. It uses the CSMA/CD protocol to determine when devices can transmit data over a shared medium, such as coaxial cable or twisted pair cables. Ethernet has evolved to support higher data rates up to 10 Gbps through standards like Fast Ethernet, Gigabit Ethernet, and beyond. Devices on an Ethernet network include end stations like PCs and servers, and intermediate devices like switches, routers, and repeaters.