In a computer network, each machine must have a network card installed to communicate with the network router. The router directs traffic on the local network and also handles requests made to the Internet, and subsequent responses. The network card in each machine must support the same protocols as the network router so that all devices are speaking the same language. A network adapter can substitute for an internal network card when a card is not present, or when the internal card does not support the required standard.
There are two basic types of networks: wired and wireless. Network adapters are made for both types of networks, with more variety among the wireless flavor as there are different types of wireless networks.
A network adapter made for a wired connection is a small USB dongle that features an Ethernet port. Ethernet cabling connects computers in wired networks, with the RJ45 Ethernet port resembling a standard RJ11 telephone jack on steroids. The adapter might come with software, though most modern operating systems will recognize a USB network adapter and apply the proper drivers upon detection of the device. Once recognized by the system, the external network adapter can be used to connect the computer to the network by running an Ethernet cable from the router to the network adapter.
In most cases, however, when people refer to a network adapter, they are referring to a wireless network adapter. These devices are popular for mobile computers, as they allow the computer to connect to the home or office wireless network from anywhere in the vicinity without being tethered by Ethernet cable.
A wireless network adapter looks similar to a memory stick or thumb drive: a small USB dongle with an LED light that indicates power and operability. Upon plugging it in, it will scan the airwaves for local broadcasts, working with system software to display the names of local networks for the user. Click the name of the network you wish to join, and supply credentials as needed. That’s all it takes to surf wirelessly. The next time you boot, the device will automatically log you into the network of choice.
Most laptop computers come with a built-in WiFi® card, or wireless network card, but there are times when the supplied card won’t do. This is especially true when wireless standards are changing from one protocol to a newer, faster protocol. Older cards that only support the older protocol will not work with routers that only support the newer, faster standard. As of this writing, the current wireless standard is 802.11n, which is replacing the older 802.11g standard.
When the internal network card doesn’t support the desired standard, an alternative to an external adapter is to replace the internal card with a newer card. This is easy to do on a desktop computer, but not so easy on a laptop or notebook. Just getting to the card might entail more disassembly of the machine than many people are comfortable with. Moreover, opening a laptop can void the warranty. It’s usually easier all the way around to opt for an external network adapter.
When shopping for a network adapter, there is little to watch for except support for the desired protocols. These handy little devices can be found nearly everywhere, from the local discount department store to your favorite online retailers.