A local area network (LAN) is a group of computers that are in close physical proximity and connected to one another to transfer data back and forth. One type of connection uses a wireless adapter, which eliminates the need for network cables.
Wireless LANs evolved as a more convenient way to connect computers in the home or office. You don't have to drill holes through walls or lay down Ethernet cable.
The wireless LAN adapter is a device installed inside the computer, or it can be an external device connected with a USB (Universal Serial Bus) cable. It is basically an antenna that tunes in to the network.
The wireless LAN "antenna" tunes in to a wireless router somewhat like a radio station, which all the computers on the network connect to so that they can "see" each other.
Ad Hoc Networks
Alternatively, you can create an "ad hoc" network, which doesn't use a router or other hublike network device. However, this type of network might have trouble connecting more than one computer to a residential high-speed modem.
You also can skip a router by tuning in the adapters to a nearby wireless modem. This device is physically attached to the network but receives wireless connections from an adapter.