I have a Brother printer/fax/scanner/copier.

No dedicated telephone lines needed.
There's a phone jack on the printer....
plug one end of the jack into the phone outlet, and the other end into the printer.

No dedicated internet line.

When a call comes into your phone, it makes a sound that is recognized by the printer/fax, which will then send a sound back to "answer" the sending fax machine...and start receiving.
When you send a fax, you type in the phone number of the receiving fax machine, and then hit "send".

You can send a fax from the printer itself, or from any PC or laptop that is connected to a home wireless router.

See below.

We have a Belkin wireless router that connects to the internet modem.
The printer is plugged into the router - it can also connect via WIFI - just like the PC and the laptops.

lori, dh says they rarely use the fax machine at his office. customers are more likely to want an email... did try to find some info and found this...

oh, i have a hp home scanner and copier. i don't like it as well as my old one, sigh..it's called a "vivera" by hp. it's also about 4 years old...it has trouble sensing whether it has paper or not...and i think it uses ink faster than my old one.

Here is a link that might be useful: http://www.consumer-rankings.com/onlinefax/?ch=3&ag=257000123&cr=2306050311&ad=162866190&match=b&term=home%20fax%20machine&kw=fax%20machine%20at%20home

I have one but I have never used the fax. Everyone I deal with would rather have any documents scanned and emailed and that is how I receive them as well. I have an inexpensive HP - works great for scanning, printing and copying. I think HP printers are more user friendly in terms of the software that you install and use with them. Their support is also very good. I learned that the hard way with the one non-HP printer that I bought from Brother.

"I'm mostly interested in the fax.

How does the fax work?

Does it need a dedicated telephone line or does it use the a dedicated internet line?"

A fax machine does, indeed, need an analog telephone line. Whether or not you have an analog telephone line dedicated strictly for incoming/outgoing faxes would depend on how many faxes you expect to be sending/receiving. If you're just going to send an occasional fax, you can just use your regular home (analog) telephone line -- just unplug the line cord from the phone and plug it into the phone jack on the machine.

"When a call comes into your phone, it makes a sound that is recognized by the printer/fax, which will then send a sound back to "answer" the sending fax machine...and start receiving."

The sound that is made is that high-pitched sound you hear if someone mistakenly sends a fax to your phone rather than to the fax machine they intended to "call." Yes, if you have a line cord ALWAYS connected to your fax machine, the machine will recognize it, but it puts a "crimp" in the way you "do business" as far as answering the phone is concerned. If you don't have a dedicated fax line, your phone could ring, you'd answer it and hear that high-pitched squeal, then you'd have to quickly stick the phone line into the fax machine's phone jack, and then press whatever sequence of buttons/numbers you need to press to have the incoming fax call manually answered. Not having a dedicated phone line is a pain in the patoot for incoming faxes.

There are plenty of places/business, etc. that need a document FAXED rather than a scanned document e-mailed.

Lindsey...Many telephone lines today are digital.
The combination printer/fax machines don't require manual pickup like the older ones did.

NO need for a dedicated line, or manual intervention to receive faxes.

We never have to manually pickup the phone - haven't for years...when the incoming fax sound is received, it automatically is directed to the fax.

BTW - my Brother color printer/fax/copier/scanner was less than $100 - new, at Staples.

A fax doesn't always have to be set to receive and a dedicated line is not REQUIRED, however if you have need to receive faxes 24/7 and not be there to attend to it if you use the phone line for other things, then a dedicated line is more important. If you simply need to send and/or receive a fax on occasion, then your current line will work.

You could even use fax software on your computer to fax. This was my preferred method when I'd prepare letters, contracts, reports, etc on the computer, then fax it out of the computer and receive faxes into the computer and use my printer to print them out rather than use the thermal paper that many faxes use or an inkjet, etc. Once I started needing to fax other peoples' forms that needed to be filled in and the like I bought a cheap standalone fax machine to send them (rather than scan them into the computer and fax it out of the PC and still receive them on the computer.

There's also email to fax and fax to email services available. For a while I had a "fax number" and then it converted the fax to an email and emailed it to me. I did a few sending faxes over the internet too.

For the unit. The combination units, called 4in1 when it has fax, scan, print and copy capability (a 3in1 doesn't have the fax ability) and they can be a flatbed scanner or a sheetfed scanner (similar to a conventional fax machine. Sheetfed are handier if you send multiple pages regularly. This is why I bought a fax machine (new for about $16) when I had to send multiple pages.

The units normally will have a built in phone so you can use it as a regular phone - thus eliminating the plug/unplug all the time. There's a setting to sense fax receiving and it can be off and if you hear the fax tone, just hit receive and it'll receive the fax. Or you can set the fax to pick up after, say 5 rings as long as a voicemail or answering machine doesn't pick it up.

There's machines and software that will sense whether it's a voice call or fax and adjust accordingly. If it hears the tone it'll work like a fax and receive it. If it doesn't get the fax tone it'll work like a voicemail/answering machine.

There's a number of options, depending on need and budget.

cynic....my 4in1 has both sheet and flatbed capabilities. Most of those sold have both, for the past couple of years, at least.
Also, my Brother 4in1 does not have to be plug/unplugged into a standard phone...it senses the signal, and goes to the printer for faxing or the voice mail if a phone call is not answered by picking up a handset in the house.

Also, with my 4in1, I can fax a file directly from my laptop, instead of having to print and then scan for faxing.

I can also set the fax to receive to the laptop.