How Ethernet Works

We can classify network technologies as belonging to one of two basic groups.Local area network(局域网)技术连接许多设备,relatively close to each other, usually in the same building. The library terminals that display book information would connect over a local area network.Wide area network(WAN) technologies connect a smaller number of devices that can be many kilometers apart. For example, if two libraries at the opposite ends of a city wanted to share their book catalog information, they would most likely make use of a wide area network technology, which could be a dedicated line leased from the localtelephonecompany, intended solely to carry their data.

In comparison to WANs, LANs are faster and more reliable, but improvements in technology continue to blur the line of demarcation.Fiber optic cableshave allowedLAN technologiesto connect devices tens of kilometers apart, while at the same time greatly improving the speed and reliability of WANs.