Fax machines combine a low-resolution image scanner with a printer. When sending a fax, the document passes over a sensor that converting the image into digital format. Data transmits over phone lines to the recipient fax machine, then converts it back to an image and prints it out.

Thermal fax machines, use heat-sensitive paper, have become obsolete, due to newer technologies. Now, fax machines incorporate an inkjet or laser printer engine providing excellent quality.

How To Shop For A Fax Machine
First, determining your needs. Will you mainly receive faxes, send faxes, or benefit from a combination of both sending and receiving? Decide between a fax-only machine and a multifunction machine.

A multifunction machine provides additional features, like a computer printer combination. 

Fax-only machines are less expensive. If you already own a high-quality printer, a multifunction device probably isn’t necessary.

Are you primarily going to use your fax machine to send faxes? Then an inexpensive model that simply sends and receives faxes is all you need. 

Do you need to send and receive faxes? Then consider a model that has a deep paper-tray, an inkjet or laser printer, a high memory capacity, and speed dial.

High transmission speed is important for sending and receiving a large volume of faxes. The fastest fax machines will send and receive at around 33.6 Kbps; however, machines have a top speed of 14.4 Kbps. 

Broadcasting - A fax machine feature allowing users to send a fax to multiple numbers simultaneously.

Kilobits per Second (kbps) - A measurment of transmission speed where 1kbp is equal to 1,000 bits of data.

One-touch dialing - A programmable feature for storing commonly used fax numbers.

Plain paper - A type of fax machine that prints on common, flat printer paper.

Resolution - The measure of the sharpness of the printed image, dots per inch (dpi).

Thermal paper - A fax machine that prints on rolls of paper through heat transfer.

Multi Function - In addition to faxing, this type of machine can scan or copy documents as well as miscellaneous functions.