IEEE 802.3 is a working group and a collection of standards defining the physical layer and data link layer's media access control (MAC) of wired Ethernet. The standards are produced by the working group of the Institute of Electrical and Electronics Engineers (IEEE). This set of standards generally applies to local area networks (LANs) and has some wide area network (WAN) applications. Physical connections are made between network nodes and, usually, various network infrastructure devices (hubs, switches, routers) by various types of copper cables or optical fiber.
802.3 standards support the IEEE 802.1 network architecture.
802.3 also defines a LAN access method using carrier-sense multiple access with collision detection (CSMA/CD).