The Public Switched Telephone Network (PSTN) is what most people think of as a phone network. This is the system that handles connections between phone numbers, making it possible to dial a number and connect to another person. The PSTN is a paid access network with connection service offered by the "phone company".

Voice over IP (VoIP) technology is a telephone network that operates over an IP (internet protocol) network. Both public and private IP networks exist, with the most common public network being what most people call the "internet". Given the enormous reach of the internet, an IP telephone network has the potential to reach people all over the globe. VoIP is the most revolutionary thing to come out of the telephony industry in the last 100 years. This technology presents a powerful solution by connecting remote phone users that place calls as if they were in the office, and the ability to create your own phone network.