Gigabit ethernet is the evolution beyond Fast Ethernet. It is… a lot faster. The “Gigabit” stands for 1 gigabit of data per second, or Gbps. This translates to 1000 Mbps which you may recognize as being really freaking fast.
To be honest, very few devices and connections manage to use up an entire Gigabit system, though many split it into multiple Fast Ethernet connections effectively from a central network point.
Gigabit ethernet works the same way Fast Ethernet does, through twisted copper wires. Specifically, it can be run through any Cat5e and Cat6a cable if configured correctly. Just as Fast Ethernet was designed to work with the original Cat5 cables.
For short distances (inside a home or building, but not between estates), Gigabit Ethernet is an unbelievably powerful way to transfer data at break-neck speeds and/or distribute high-speed access to multiple endpoints inside the network.