The Voice over IP, which is also often called VOIP or IP telephony, is a term that defines a system that makes transmitting voice and multimedia sessions through any Internet Protocol (IP) network possible.
A clear example of an IP network is the Internet. Respectively, all kinds of communication services provided via the Internet (such as SMS, fax, or voice-messaging) are examples of VOIP.
Voice transmission offered by VOIP systems has a number of benefits. The most significant advantage is lower setup and maintenance costs compared to traditional telephony infrastructure.