Definition - What does Internet Telephony mean?
Internet telephony is a type of communications technology that allows voice calls and other telephony services like fax, SMS and other voice-messaging applications to be transmitted using the Internet as a connection medium. Software under this technology is cost-effective and convenient because it allow the user to communicate through fax, voice and video calls anywhere in the world as long as there is an Internet connection. In this way, users are able to bypass the charges that are common in traditional telephone services. However, the quality of this service is not as good as that of traditional circuit-switched networks used in traditional telephone services because it is very dependent on the quality and speed of the Internet connection.
Internet telephony is also called IP telephony or broadband telephony.
Techopedia explains Internet Telephony
Even though Internet telephony and Voice over IP (VoIP) are used synonymously, they mean two different things. Internet telephony is defined as the umbrella technology, the one that encompasses all use of Internet Protocols (IP) for voice and telephone-like communications transmitted over the public Internet. VoIP, on the other hand, is simply one technology under Internet telephony.
Internet telephony includes a wide range of communication involving various digital phone systems based on numerous IP addresses. It was developed in order to increase productivity by taking advantage of the Internet and various applications attached to it. In contrast, VoIP is merely a digital medium for voice calls offering cheap or free voice calls while adding more voice communication features.