The speed of data transfer on a wired connection depends on Cable, Connector and the Crimping.
Ethernet over Coax (EoC) co-axial cable. Optical and Gigabit Ethernet over Optic Fibers. Copper twisted pair and others are other means of Digital Data Transfer over Ethernet.
Wi-Fi and WiMax helps freeing the user from wires. Remember Wired is more secure than Wireless.
Building a RJ-45 Ethernet cable of a specific length
RJ-45 connectors and coloured caps; the latter helps to protect the ethernet connector as well as they differentiate the cables in the muddle of cables a network can produce!
Down flat... and in the right ordre to be manipulated; from left to right: white/orange, orange, white/green, blue, white/blue, green, white/brown, brown