Voice over IP is short for Voice over Internet Protocol, and is better known as VoIP.
Voice over IP refers to the transmission of voice traffic over internet-based networks instead of the traditional PSTN (Public Switched Telephone Network) telephone networks. The Internet Protocol (IP) was originally designed for data networking and following its success, the protocol has been adapted to voice networking by packetizing the information and transmitting it as IP data packets.
Unified Communications (UC) is a business term describing the integration of enterprise communication services such as instant messaging (chat), presence information, voice (including IP telephony), mobility features, audio, web & video conferencing, desktop sharing, data sharing (including web connected electronic interactive whiteboards), call control and speech recognition with non-real-time communication services such as unified messaging (integrated voicemail, e-mail, SMS and fax). UC is not necessarily a single product, but a set of products that provides a consistent unified user interface and user experience across multiple devices and media types
A Hosted PBX is a private branch exchange (PBX) delivered as a hosted service. It’s also known as a Virtual PBX and the advantages companies that use it experience are the elimination of installation, operation and maintenance costs of their VoIP PBX as their VoIP service provider hosts their PBX for them.
A Hosted PBX still allows companies to utilise and take complete advantage of their phone system’s feature set such as voicemail, faxing, automated greetings, conferences and so on.
Companies that offer Hosted PBX’s as a service to their customers handle the call routing or switching as well as all maintenance involved in the hosted PBX service.