EXTRACT FROM MICROSOFT
What you need
If you're planning to send and receive faxes at home, you first need to outfit your PC with a fax modem.
A fax modem is a relatively inexpensive piece of add-on hardware that allows your computer to communicate with a fax machine over a standard phone line. The devices are sold at major computer stores and come in two varieties: internal and external.
Internal fax modems plug directly into your computer motherboard, similar to the way a video or sound card is plugged in. External fax modems are small devices that connect to the serial or USB ports.
If you're at work, another option is to see if your employer has a fax server—a dedicated computer equipped with multiple fax modems. Sending a fax using a fax server doesn't require you to add any special hardware to your PC. You just set up a connection with the fax server and go.