Ethernet cable is used used to connect to networks. They connect to computers, printers, hubs, switches, and bridges to transfer information. It can be identified by having 8 nodes at the end and is typically blue or white, but can be any color. The wires inside are twisted in pairs of colors (a solid color and one that twirls with the same color and white) that are colored red orange green and blue. The wires do not have to be in any particular order other than both ends must have the same pattern which has led to some major upgrading problems since every company has its own standard. Most Ethernet communications cannot exceed 10MB, but there are some that reach 10GB and 100GB is now being developed. Ethernet makes up much of the home connections today along with wireless. Fiber-optics is used in the "backbone" of the internet because it has more speed as it uses light instead of electronic pulses to send information, but it is exceptionally more expensive. If you want more information you can look up the IEEE 802 standards.