So let's say you have a wireless network and it's just not big enough. Your apartment is really big or your house has a lot of rooms in it and you're just not reaching all the points you wish you were.
What you need is something called a range extender or a bridge. What they look like is basically like this. They look like another router but they act in a slightly different way. Instead of having just one radio antenna in them, they have two radio antennas in them. One that grabs the Internet connection from your current router, and another that spreads it on.
So you would want to put this wireless ranger extender at kind of the halfway point between where you computer is and where your router is. The place where you could still get pretty good reception, but it's not perfect. So that the wireless router can take that signal and kind of bounce it off to another area of the house that previously did not have coverage.
The way this range extender or bridge will extend the network, is by creating a second wireless network that you can log into. So you can name this network, you know, network A and this network could be network B and both of them will actually combine with this range extender and be a part of one network. It will be listed on the computer as two separate networks, but it doesn't really matter which one you connect to. All the devices will be able to talk to each because they're all basically on the same area.