What Is Ethernet?
Ethernet is a type of connection between computers that forms the basis of most Local Area Networks (LAN). It also serves as one of the main methods for connecting a computer or network to an Internet hub. The origin of Ethernet was the idea of connecting several computers together in a network via coaxial cables; since that time it has evolved into a much more sophisticated system that uses specialized Ethernet cables that connect to a central hub or router in order to network several computers together.
There are three main pieces of Ethernet hardware: Ethernet cards, or adapters, Ethernet cables, and Ethernet routers and hubs. The Ethernet card, or adapter, is the component that is actually installed in each computer that connects to the network via Ethernet cable; it is the hardware that the computer uses to transmit and receive data packets across the network and the Internet. Ethernet cables come in a number of styles, with the most common being Category 5 (Cat5) or Category 6 (Cat6) cables. The cables contain several wires which allow for the transfer of data in both directions to and from the computer. The final hardware component is the hub, or router, that is used by the network; this hardware directs the intra-computer data across the network so that the correct computers can share it and also can serve as a link to the Internet.
Ethernet and the Internet
When using an Ethernet network, the network's router also serves as a bridge to the Internet. The router connects to the modem, which carries the Internet signal, sending and receiving data packet requests and routing them to the proper computers on the network. Even if a network isn't being used and only a single computer is present, in most cases that computer will connect to the modem by means of an Ethernet cable (or if a wireless router is being used, then the router will be connected to the modem).