Send a fax from computor?

I know it should be common sense but do you have your phone line plugged into your computer? because even if you have internet, I think the actually fax has to go through a free phone line.

Hi first of all why the need for the computer if you already have a fax machine? I mean if you have a standalone fax machine then you don't need your computer and if you are going to send fax from your computer then you don't need a fax machine.

Either way you need a phone line connected to the computer or fax machine.