The difference between an automated answering service and an answering machine is that an answering machine only allows callers to leave a voicemail, whereas an automated answering service provides other options, such as routing to a specific person or department or adding business hours.  Automated answering services can even answer common questions from callers without them having to speak with a real person. Answering machines are not as advanced as automated answering services, although all automated answering services will include some type of voicemail or answering machine capability.