The language and physical configuration of a local area network (LAN) that interconnects multiple PCs, printers, servers, or other devices. Chances are if you look behind your office PC to see how it’s connected to the local area network, you’ll see a thick wire attached to a connector that’s slightly wider than an RJ-11 phone jack. The wire is known as “category 5,” the connector is RJ-45, and you’re on either a 10 Mbps or a 100 Mbps Ethernet connection. Ethernet is a critical enabler for most high-speed cable and DSL service connections.
The identifying characteristics of Ethernet are its data rate (in the Gigabits per second, at this point), its maximum link length (around 500 meters for coax, and 100 meters for twisted-pair copper), its media type (coax, fiber, twisted pair) and its topology (the “shape” of the network — bus, star, point-to-point.)
Ethernet also describes how interconnected things communicate. Say you’re a device that speaks Ethernet. You’re at a cocktail party with 30 other Ethernet devices. Mostly, everyone stands, sips and listens (to nothing, because no one is talking.) If you happen to blurt your packets at the same time someone else is blurting packets, your blurts collide. You stop talking, wait a random amount of time (measured in micro-seconds), then repeat what you said. So does the other person. The random wait interval helps to assure that you don’t collide again.
Usage: Ethernet was invented in 1973 by Bob Metcalfe, who founded 3Com and is one of the generally acknowledged “grandfathers of the Internet.”