dear friend voip is short for voice over the ip and it's simply a phone that uses a LAN (local area network) insted of the regular phone line
so what you need for this phone to work is : an internet connection, a router and a broad band modem. the router is a device that enable you of making a local network and it's either wireless or wired
the router is usually connected to the modem then to any other network enabled device like a network printer or a network hard drive or a network dvd player or the voip phone and to the other computers in the network
there are a lot of advantages for that kind of phones like that you can take it to any where in the world and use it with the same number as long as there is an interner connection
a wireless router and a wireless access point is the same thing
if you're looking for more info you can search on line