Wi-Fi Protected Setup (WPS) is a wireless network setup solution that lets you automatically configure your wireless network, add new devices, and enable wireless security. Wireless routers, access points, USB adapters, printers, and all other wireless devices that have WPS capabilities can all be easily set up to communicate with each other, usually with just a push of the button.
Typically, there are a few steps to setting up a wireless network. With WPS, the number of steps required to set up a network can be reduced by about half. You push a button on the router or enter a PIN number to network the devices. One of the advantages of WPS is that you don't have to know the network name or security keys to join a wireless network; these are created for you and authentication uses a strong authentication protocol, EAP, that's used in WPA2.
A disadvantage of using WPS is that if some of your devices aren't WPS-compatible, it can be harder to join a network set up with WPS because the wireless network name and security key are randomly generated. WPS also doesn't support ad hoc wireless networking.
As with the phrase "Wi-Fi", Wi-Fi Protected Setup is a trademark of the Wi-Fi Alliance, an international association of companies involved with wireless LAN technologies and products. You can view a demonstration of Wi-Fi Protected Setup at the Wi-Fi Alliance's website.