Ethernet is a communication method for computer networks that was first invented by Bob Metcalfe in the late 1970s. He called it the "Ethernet" after the mystical ether, which was once thought to fill space and through which light and radio waves were supposed to move. Like the original ether, the Ethernet did not discriminate. It was built to carry information from any computer to any other kind of computer. Ethernet uses cables and switches to connect together computers, servers and even IP telephones and other devices within local area networks, and is rapidly expanding to wide area networks and metropolitan area networks. It became a free, public standard in the mid-'80s, which helped make it cheap and popular.

Today, Ethernet dominates the networking landscape. Its only serious competition, IBM's Token Ring network, was finally scrapped this past spring.

Ethernet originally worked at a rate of 10 megabits per second. In 1995, 100 Mbps Ethernet was released, which was followed by gigabit Ethernet in 1998. The latest improvement, 10-gigabit Ethernet, was approved by the standards-setting bodies last summer. The next increment is expected to be 40 gigabits within the next four or five years.

The original genius of Ethernet was that it consisted of a single long cable to which computers were attached. The individual computers handled all the thinking for the network-figuring out which messages went where. They scanned all the message traffic to see whether any was relevant to them.

In the 1990s, Ethernet was improved by the addition of smart switches to the network, reducing some of the burden on individual computers. This made the Ethernet more scalable and efficient.