As just mentioned, Wi-Fi hardware has to be certified by the Wi-Fi Alliance. Throughout this article I will assume non-certified devices and use the “wireless network” phrase rather than “Wi-Fi network.”
The hardware basically consists of a transmitter, which emits the wireless signals and receives connection requests, and a wireless client that sends the requests and receives the replies from the transmitter. Opening up these terms, the transmitter is the wireless router, which is most probably connected to a modem (or if it’s equipped, directly to the phone line) and a laptop, mobile phone, or PDA that is capable of connecting to the wireless network.
To make the connection, a wireless router has to be configured as an access point first. You can read more about this in our article that is specifically on this topic. However, if you only have a wireless router that is capable of a USB connection only, then you need to configure your computer as an access point, which is a good weekend project. Therefore I strongly advise you to have a router with at least one Ethernet Connection.
The mobile devices which will connect to the wireless networks have wireless cards or built-in wireless circuitry. These cards come from different manufacturers such as Intel, Broadcomm, and Atheros, to name the top three. Network cards are present in laptops (either built in or plugged in from the Express Card, PCMCIA, or USB ports), PDAs, and recent mobile phones.