Wifi printers - good job if you don't like kicking against your printer under your desk.
Can you also print from a remote location on the web with them generally?
If I understand what you are asking, the answer is generally no.
The device will be physically (well wireless-ly!) connected to your network and only devices on your network will be able to print to it.
If you have VPN or some sort of remote access utility that gets on to your network, you should be able to.
Also, on thinking about it you could probably forward certain ports from the internet to the printer and then print from anywhere by using your internet IP as the address of the printer (you will need nat loopback to print from within the same network). That being said, I really wouldn't advise you do this, but I wonder if anyone does!