Cubix is a Softphone - The term softphone is short for software telephone and that's just a fancy way of saying Internet telephone. Cubix is essentially an Internet telephone that allows you to make free phone calls to other people who are also running the same software on their computers.

Traditional telephones use phone lines that run back to your local telephone exchange to make phone calls. When you call someone, your local phone exchange sends the call to the phone exchange nearest the person you are calling and the phone company charges you for the call. When you make a call using Cubix and VoIP, your voice is first turned into digital packets which can be used by your computer. These packets are then sent over the Internet from your computer to the computer of the person you are calling where the packets are turned back into voice. The wonderful thing about this is that it does not cost you anything beyond your normal ISP costs!

You will of course need to be connected to the Internet to use Cubix and VoIP, but the actual softphone call costs nothing! And it does not matter if the person you are calling is across the road or on the other side of the world, since the call is sent over the Internet.