A virtual call center is the combination of different agents from different locations, which brings all these agents together into a single call center. The call center is not located at a single location where all agents are located in one building.
Voice Mail is the modern variant of the answering machine. A voice mail is characterized by the fact that it can be sent as an e-mail and can therefore be played back on almost any modern communication device. All the classic functions of an answering machine are provided by the voice mail system, such as monitoring, remote enquiry, …