WLANs are generally composed of two basic elements: access points and other wireless-enabled client devices, such as laptop computers. These elements rely on radio transmitters and receivers to communicate with each other. Access points are physically wired to a conventional network and provide a means for wireless devices to connect to them.
Wireless LANs were originally designed to substitute for wireline LANs; to be used where wires were either too costly to install or where added flexibility (to move computers easily and/or quickly) was needed. For example, many older buildings are difficult to wire for computers (or even phone lines) because of their construction or the presence of hazardous materials such as asbestos. In these cases, wireless LANs may provide a cheaper solution.