Ethernet (IEEE 802.3) is the dominant wired LAN technology. Uses MAC addresses for addressing, CSMA/CD for collision management (legacy half-duplex). Modern = full-duplex, no collisions.
Modern switched Ethernet is full-duplex — each port is its own collision domain. CSMA/CD is irrelevant in full-duplex. Ethernet frame: Preamble + Destination MAC + Source MAC + EtherType + Data + FCS. Maximum frame size: 1518 bytes (standard), 9000 bytes (jumbo frames).