A wireless device can refer to any kind of communications equipment that does not require a physical wire for relaying information to another device. Wireless headphones fitted with a receiver use either radio frequency (RF) or infrared technology to communicate with a transmitter that is connected to the sound source, say a television. In most cases, however, when someone refers to a wireless device, they are speaking of a networking device that can pass data to other wireless network gear without being physically connected.
In today's world, where people put a premium on staying connected to the Internet and to each other, there are several types of wireless technologies. In the home and office, wireless routers with built-in modems, hubs and switches broadcast a local area network (LAN) for computers in the area to join. Broadcasting distance varies widely depending on many factors, but a LAN generally spans 300 feet (91.44 m) or more. Any computer on the network can share resources that are connected to the network, including a high-speed Internet connection, printer or other office equipment.
In order to join a wireless LAN (WLAN), a computer must have a wireless network card or adapter installed. A network card is an internal wireless device manufactured to use the same language or protocol that wireless routers use. These protocols periodically evolve into new standards, however, causing compatibility issues in the interim. If a router uses a protocol that is not supported by an internal wireless device, an external wireless adapter can be used in an external port. The most common type is a USB dongle, but wireless network adapters are also available in ExpressCard formats, giving laptop users a choice as to which port they would rather use.
Another type of wireless device might be part of a Personal Area Network (PAN). A PAN is created with Bluetooth technology, designed to connect personal digital devices over very short distances of just a few feet, though the standard extends to 30 feet (9.14 m).
Bluetooth is a very flexible and convenient type of network. It can be used to send print jobs from a laptop to a nearby printer without the hassle of setting up shared resources over a LAN. It is also used to connect Bluetooth-enabled cell phones, personal digital assistants (PDAs), or Apple products to each other or to other Bluetooth-enabled equipment including headsets, external speakers, or computers. Since Bluetooth uses a different frequency range than LANs, you can use a Bluetooth network "within" a LAN without interference.