In a word: money. Internet telephony is cheap. An all-you-can-eat local and long distance dialing package can cost as little as $19.95 a month. You won't find any mainstream, traditional calling plans that meet these rates.
With traditional telephone service, sometimes referred to as POTS (Plain Old Telephone Service), voice signals use telephone lines — copper wires — and circuit switches to communicate. Internet telephony eliminates the telco company all together by using computer networks to send voice signals. All information is transferred across the Internet in "data packets." For example, if someone sends a friend an , the email is broken up into a series of data packets that each take their own route to the destination . Once there, the packets reassemble themselves into the full email message.
Internet telephony also transmits using data packets. Analog voice signals are digitized, sent in discreet packets to the destination, reassembled and reverted back to analog signals. By using this system, a person can place long-distance calls free of telephone charges. The catch is that both parties must have the correct software. If this technology is used to call a land-line or cell phone, charges apply, though they are usually minimal.
Internet Phone is another word for and is also known as Internet calling or Internet telephony. Internet Phone is a great way for people to save money on their monthly phone bill due to the low costs, big features, and voice quality that traditional phone services can't match. Internet phone service is available for your as well as your , and is offered by a number of big name providers.