A network can be defined as two or more computer terminals connected in a way that facilitates the sharing of data. A network can be as simple as two computers with limited access to a few of each others' files or as complex as hundreds or even thousands of client terminals, hubs, and routers all connected seamlessly, feeding data to each other. Ethernet has been the standard for computer Local Area Networks (LANs) since the mid-1990s.

An ethernet crossover cable is most often used for very simple networking scenarios, often for networking only two computers. Often, there is a need for a simple method of connecting two terminals in a network without the use of a hub or router, either because there is no hub or router available or just for the sake of simplicity. An ethernet crossover cable can alleviate the need for such a hub as a result of its unique design and functionality.

An ethernet crossover cable is similar in appearance to a standard ethernet cable except that it has its "send" and "receive" wires crossed, allowing for a back-and-forth communication between the two computers (hence the "crossover" name).

Additionally, many hubs, routers, and modems have internal crossovers to allow users to directly connect a computer to them without the need for a crossover cable. However, if the user wishes to connect a succession of these items, a crossover cable is needed to reverse the original crossover so that they communicate normally.

This scenario would usually take place when connecting a DSL or cable modem to a hub for extended networking applications. If the user simply wished for one client computer to have access to the internet, a standard ethernet cable connected between the computer and the modem would suffice. However, if there is a need for multiple computers to access the internet, then a hub is required. The hub is connected to the router via an ethernet crossover cable, and the client computers are then connected to the hub via standard ethernet cables.

Ethernet crossover cables save time and confusion by allowing a dual-directional communication pathway between computers or computer networking devices such as hubs, routers, and modems. They can also spare users the added expense and complication of the use of a hub in simple two-computer networks. Ethernet crossover cables can be found reasonably online or in most computer supply-related stores and distributors.