Your computer is by no means an island. It can share its files -- and the peripheral devices connected to it -- with other computers. This is called networking, and it can be as simple as two computers sharing files or as complex as thousands of computers sharing everything from databases to networked printers.

Your computer uses a networking port to accomplish this task. These ports move the data from the computer onto the networking cable and through the network to the proper device.

The network card fits inside the computer in one of the empty internal pci slots or in many cases are built right onto the motherboard itself.

Network ports or cards, also called "LAN" or "NIC" cards, follow a set of standards by the IEEE as specification IEEE 802.3; referring to the Ethernet design or as a compatible with Ethernet.

"10 Base-T or 10/100" port: a common type of Ethernet port that looks similar to a telephone jack, called RJ-45. This type of connection is by far the most popular and is commonly found on local area and peer-to-peer networks that are constructed like a star, with multiple lines branching out from a central network server or hub to each machine on the network.

"Coaxial BNC" or "Thinnet" connector: This jack is like the connection commonly found on cable television devices. Networks using Coaxial BNC or Thinnet typically are constructed using a "daisy-chain" topology, with computers strung out in a row on the network like beads on a necklace.

Most of today's networking and internet technologies like DSL and Broadband modems provided by an ISP (Internet Service Provider) employ Ethernet connections. This is why you will find over 90% of today computers sold over the counter with built-in LAN cards as well as 56K modems. BNC connections are still used, but is less popular due to issues surrounding length and quality of data transmission over the wire medium. A main inbound internet/broadband connection, for example, would use a BNC, but the infrastructures network would then be served by devices connected on an Ethernet LAN.