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 on each machine must support the same protocols as the network router so that all devices speak the same language. A network adapter can replace an internal network card when a card is not present or when the internal card does not support the required standard.
A wireless network adapter.
There are two basic types of network: wired and wireless. Network adapters are made for both types of networks, with more variety between wireless types as there are different types of wireless networks.
Cat 5 cable with RJ45 plug.
A network adapter made for a wired connection is a small USB dongle that has an Ethernet port. Ethernet cabling connects computers on wired networks, with the RJ45 Ethernet port looking like a standard RJ11 phone jack on steroids. The adapter may come with software, although most modern operating systems will recognize a USB network adapter and apply the appropriate drivers when detecting 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.
However, in most cases, when people refer to a network adapter, they mean 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 nearby without being connected via an Ethernet cable.
A wireless network adapter is similar to a memory card or USB stick: a small USB key with an LED light that indicates power and operability. When plugged in, it will scan the radio waves for local broadcasts, working with system software to display local network names to the user. Click the name of the network you want to join and provide credentials as required. That’s all it takes to browse wirelessly. The next time you start, the device will automatically log in to the network of your choice.
Most laptops come with a built-in WiFi® card or wireless network card, but sometimes the provided card doesn’t work. This is especially true when wireless standards are changing from one protocol to a newer, faster one. Older cards that only support the older protocol will not work with routers that only support the newer, faster standard. At the time of this writing, the current wireless standard is 802.11n, which is replacing the old 802.11g standard.
When the internal network card does not 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, but not so easy on a laptop or notebook. Simply pick up the card to dismantle more of the machine than many people are comfortable with. Also, opening a laptop can void the warranty. It is usually easier to opt for an external network adapter.
When shopping for a network adapter, there is little to consider except support for the desired protocols. These handy little devices can be found just about everywhere, from your local discount department store to your favorite online retailers.
