Ethernet is, quite simply, plugging your network directly into a telecom provider’s network. When you bypass the local phone company you cut out an expensive transport step. Having direct access to customers is a carrier’s goal as it allows them to control the user’s experience from end to end while reducing cost. These savings are passed on to you. It also establishes a direct relationship with a provider without the local Bell in the equation. And since the Ethernet carrier is in complete control of your connection, it is much easier for them to provide QoS.
Fast Ethernet is a term to describe various Ethernet services that have a speed of 100Mbps. Traditionally the most common speed of Ethernet was 10Mbps, thus the term FAST Ethernet.
Ethernet speeds of 1000Mbps (a gigabit) are also possible. This is called Gigabit Ethernet or GigE.
Ethernet over Copper is a technology that uses copper as a delivery method for Ethernet to the business premises. Ethernet over Copper can be very cost effective. It doesn’t require any fiber, and runs on 5 pairs of copper. The reliability is good as well, and even with just one of the five copper pairs left you still have Ethernet (at a lower speed). Currently the maximum distance for Ethernet over Copper is 9000ft from the phone company’s CO. If you are further away, Ethernet over Serial (EoS) may be an alternative. EoS is delivered over multiple DS1 loops. It is slightly more expensive than Ethernet over copper.