Okay with all these technical words flying around, maybe a little primer is in order for me and everyone else. I'm trying to remember what I did when I had DSL from Qwest over a land line. Technologically, this was a loooong time ago -- maybe five digital dog years. All this talk of modems and wifi routers can send a person's head spinning. A couple of definitions are in order:
MODEM: It's that box with flashing lights that connects your computer to your ISP (Internet Service Provider), which typically provides either cable or DSL Internet service. DSL modems have a telephone connector, also called an RJ-11 jack, which plugs into a telephone socket on the wall. (Cable modems have a coaxial -- or "coax" -- connection, which is the same type of connector found on a TV or cable box. This connects to a cable port on the wall.)
INTERNET ROUTER: This is the device that allows several other computers to use the Internet at the same time. A wireless router creates a local wifi signal.
To get a wifi signal with DSL, plug the the modem into the wall telephone socket, then link the modem to the wireless wifi router using an ethernet cable. There was a CD that came with my wifi router and it walked me through the process of setting it up and creating a password. You need a password to provide security so you can do your banking & other confidential stuff on line. It does not make your email secure, however.
Follow the instructions from Avalen on hooking onto a wifi signal. If you need help doing this, ask a nine-year-old (no kidding) for help. BTW, while your ISP probably requires you to rent its modem, you can buy a perfectly fine wireless router at Radio Shack. You don't need to rent theirs.
I gave up my land line in favor of just my cell phone and now I am an untethered American. Before I did this, I would just ask my telephone provider to put my home phone & DSL on vacation hold when I headed out on the road. I have an iPhone and it has a "hotspot" function -- meaning it creates like a little wifi "bubble" around me. (No need for those silly modems or routers.) I use it when I travel, and I have Verizon bump the number of gigabytes of data available to 6 gig per month when I'm on the road. That is just enough to get me by.
I hope this is not only helpful, but correct.