Definition: Fast Ethernet supports a maximum data rate of 100 Mbps. It is so named because original Ethernet technology supported only 10 Mbps. Fast Ethernet began to be widely deployed in the mid-1990s as the need for greater LAN performance became critical to universities and businesses.
A key element of Fast Ethernet’s success was its ability to coexist with existing network installations. Today, many network adapters support both traditional and Fast Ethernet. These so-called “10/100” adapters can usually sense the speed of the line automatically and adjust accordingly. Just as Fast Ethernet improved on traditional Ethernet, Gigabit Ethernet improves on Fast Ethernet, offering rates up to 1000 Mbps instead of 100 Mbps.