What is Ethernet header?

An Ethernet header is a portion of data that precedes the payload in an Ethernet frame, containing essential information for data transmission over a network. It typically includes the source and destination MAC addresses, the EtherType field to indicate the protocol used in the payload, and other control information. The header enables devices on a local area network (LAN) to identify and process the incoming frames correctly. In standard Ethernet frames, the header is usually 14 bytes long.