Network Cards and Modems

Network Cards

A network card (also known as a Network Interface Card, NIC, Network Adapter, or Ethernet card) is a device used to connect a computer to a local network or to a high-speed Internet service, like cable or DSL.

Network cards are made that will work with a variety of different wires and cables, but the most common is Ethernet, using Category-5 cable (or "Cat-5" for short) and RJ45 connectors. Cat-5 cable looks a lot like telephone cable, except that it is thicker and contains eight individual wires. The RJ45 connectors used for Cat-5 also look a lot like the RJ11 connectors used for standard telephones, except that the RJ45 connectors are wider and have eight conductors.

It's important to note that although a standard RJ11 telephone cable will "fit" into an RJ45 Ethernet jack, you should never plug a telephone cable into a NIC. The NIC could be permanently damaged.

Nowadays, most new computers have Ethernet NIC's built right into the motherboard (the main circuit board inside the computer). These are called "integrated NIC's."

Modems

The word "modem" is short for "modulator/demodulator." Modems have been around for a long time. They are used to convert a computer's digital data into a modulated analog signal that can be transmitted over a telephone line. You will need a telephone modem if you want to use a dialup Internet service or other dialup networking connection, or if you want to use your computer to send or receive faxes.

Modems these days are a lot faster than they were a decade or so ago, but they're still painfully slow compared to broadband Internet, such as cable, DSL, or satellite. Consequently, as the popularity of dialup Internet drops and broadband becomes more popular, fewer and fewer computers are coming equipped with telephone modems. If you want one, chances are you'll have to specify it in the order or add it yourself.

You can get internal telephone modems for as little as $5.00 or as much as $50.00. The cheapest ones are usually not "real" modems, but electro-acoustic couplers that use hardware and operating system resources to simulate what a real modem would do, namely, modulate and demodulate data. Better-quality modems have on-board controllers and processors that can significantly improve performance, especially during sustained data transfer (such as downloading a large file).

You can also get external modems that plug into the serial or USB ports. These usually can be had for anywhere from $30.00 to $100.00. External modems are usually (but not always) "real" modems that contain their own controllers and processors. They usually deliver good performance (at least by dialup standards) and can be installed without having to physically open up the computer. In addition, because most external modems are OS-neutral, they are more likely to work with non-Windows operating systems like Unix or Linux.