WPS stands for wi-fi protected set-up. It’s supposed to make it easier for non-tech savvy people to authenticate devices on to a wireless network by pressing a physical button on the router or entering a PIN in to a device to make it known to the network.
The problem with WPS is quite a big one. There are many fundamental flaws in the WPS model – I won’t go through these in this article but a simple Google search will expose these many vulnerabilities in WPS – one which I discovered by accident today is a relatively (scarily) easy denial of service on an end-users network.