IVR (Interactive Voice Response) is the classic touch-tone phone menu: "Press 1 for sales, 2 for support …". The technology has existed since the 1970s and relies on predefined trees plus DTMF tone recognition.
AI phone assistants replace IVR with free speech and intent classification: callers state what they want, the system parses in real time. This typically shortens call paths from 30–90 s to a few seconds and reduces abandon rates.
Field lesson: pure IVR migrations fail when the old menus are simply translated into a script. The deployments that win identify the top 5–10 intents, model them as dialogue flows, and keep IVR only as an emergency fallback.