You can access the internet wirelessly and also use wireless printers using one. You don't need to have a laptop, just a wireless adaptor. It's likely you'd have to move the PC next to the hub to start with to set it up initially but after that you can just connect from wherever it is.
if your computer is not a laptop and not going to be moved around, and as long as you are able to connect the hub to a phone line close to the computer you do not need the wireless, just use the Ethernet cable to connect to the hub and get the internet, preferably turning the wireless off altogether on the hub.
The terms for network and internet application have become somewhat muddled, mainly brought about by overzealous manufacturers.
A wireless hub is connected to your computer and send a radio signal to your wireless printer or other computers in the near vicinity on a network that have wireless capability. This saves having wires all over the place. You can not share your internet on a hub, for that you need a router.
A router takes your internet signal and send it to all wifi and wireless internet capable computers in the near vicinity. Routers are best password protected so in order for a computer to receive the signal a password has to be send from that computer to the router. This prevents others from stealing your bandwidth.
A modem is the unit that receives the phone/cable signal and deciphers it to a signal that your computer understands.
With the popularity of broadband there are now many single machines available that do all three jobs in the one unit.