It is the business practice of sending all clients' billing info to a separate company, who then does everything for you. It also allows a company to cut down on time and human resources spent on administrative tasks.
This service allows called party to listen to the audio or video announcements of callers before connection. The caller can choose a message that will be played and conditions by which the message will be plaid over. For example, before the subscriber answers the call, they will hear audio message with the name of the person who is calling.