Ethernet

Ethernet is a family of wired networking technologies for local area networks. It standardizes link-layer frames and physical signaling over media such as twisted-pair cable and optical fiber.

Ethernet frame: The link-layer unit Ethernet devices transmit, containing destination and source addresses, a type or length field, payload, and error-checking data. This standardized unit carries packets across an Ethernet link.
IEEE 802.3: The IEEE standards family specifying Ethernet media access control and physical-layer implementations. It formalizes the interoperable Ethernet technologies used on wired LANs.
Local area network: A network connecting devices across a limited area such as a home, office, or campus. Ethernet is a standard technology for building wired local area networks.
Wi-Fi: A family of wireless local-area networking standards based on IEEE 802.11. Wi-Fi serves many of the same LAN needs without Ethernet's wired links.
MAC address: A link-layer identifier used to distinguish network interfaces on a local network. Ethernet frame headers use MAC addresses to identify their local sender and destination.
IEEE 802.1Q: An IEEE standard for virtual LAN tagging and bridging in Ethernet networks. Its tags let Ethernet switches separate traffic into virtual LANs.
Gigabit Ethernet: Ethernet technologies that provide a nominal data rate of one gigabit per second. It brought gigabit speeds to common copper and fiber LAN links.
Token Ring: A local-area networking technology in which stations transmit by passing a circulating token. It competed with Ethernet in enterprise LANs before Ethernet became dominant.
Ethernet switch: A network device that forwards frames between ports, typically using learned MAC-address information. Switches connect Ethernet devices and direct frames toward their destination ports.
Ethernet PHY: The physical-layer circuitry and specification that transmit and receive a particular Ethernet signal. Each Ethernet medium and speed requires compatible physical-layer signaling.

Linked from 22 pages