A virtual PBX is a private branch exchange (PBX) phone system that is delivered as a hosted service. These are typically offered by a telephone company and can free companies from having to invest in the costly equipment of a complex business phone system. This enables the company to utilize telephony features like voicemail, faxing, automated greetings, touchtone menus, conference calling, call auditing, and calling logs.
Virtual PBX companies handle call routing, or switching, at their own location and are responsible for managing all of the PBX equipment and software involved in the virtual PBX service. Hosted PBX services can function over the Public Switched Telephone Network (PSTN), over the Internet (hosted IP PBX via Internet telephony, or VoIP), or over a combination of the two.