Ethernet

Overview
Ethernet is a classification for computer networking with local area networks (LANs) with common wiring and signaling standards. It is defined by the standard IEEE 802.3. It is the largest and most widespread networking technology, consisting of twisted pair signal cables (e.g. CAT5) for end systems, and fiber optic connected backbones. It largely usurps older standards such as token ring and FDDI, and stays current through constant evolution.

Technical Details
There are countless Ethernet technologies, but they adhere to the IEEE 802.3 standard. Simple connections can be made via coaxial cable, while hubs and switches act as junctions in the network. Despite the differences in internal device architecture, transfer methods,and transfer speed, data is transmitted in the same, consistent formats.

Ethernet devices communicate by sending data packets. Each device is given a 48- bit MAC address to help identify the sender and destination. Ideally network devices do not accept packets addresses to other devices, but this varies widely in practice.

Links

 * IEEE 802.3 Specifications