What is ethernet and how it works?

Ethernet is a protocol that controls the way data is transmitted over a local area network (LAN). It uses wired network. The wires used for a LAN are CAT 5 cable with an RJ-45 jack, which is similar than phone jack, RJ-11, but twice as big. Some Ethernet networks use coaxial cables. Ethernet is by far the most popular LAN protocol used today, that is, almost every new computer has the ethernet LAN card installed.

There are different types of Ethernet, but those used in home networks are typically 10Base-T, which transfer data at speeds up to 10Mbps or 10/100Base-T, which transfer data at speeds up to 100Mbps. Fast Ethernet also refers to 10/100Base-T. Now the fastest Ethernet reaches Gbps in speed. Ethernet uses a protocol called CSMA/CD, this stands for Carrier Sense, Multiple Access with Collision Detection. Ethernet networks can be extremely complex, but the simplest Ethernet network consists of two computers connected by a CAT 5 cable.

The design goals for Ethernet were to create a simply defined topology that made efficient use of shared resources, was easy to reconfigure and maintain, provided compatibility across many manufacturers and systems, while keeping the cost low.