Automatic call distributor

An automated call distribution system, commonly known as automatic call distributor or automatic call dispatcher (ACD), is a telephony device that answers and distributes incoming calls to a specific group of terminals or agents within an organization. ACDs direct calls based on parameters that may include the caller's telephone number, the number they dialed, the time of day or a response to an automated voice prompt.

Source: Wikipedia — Automatic call distributor (CC BY-SA 4.0)