An automated answering machine is a device that answers telephones and records messages from callers if a human does not answer the phone first within a set period of time or number of rings. Such machines usually require the owner of the phone to record a message that will be played back to the caller if the machine answers the phone. Though early answering machines recorded messages on tapes, most modern answering devices use solid-state digital storage. It should be noted, however, that a "voicemail" system, which is commonly used to leave messages for cell phone users, is not considered to be an automated answering machine, as it is generally a networked system rather than a machine attached to the phone. Additionally, automated machines sometimes are designed not to record messages, but to transfer callers to the correct party.
Personal answering machines tend to exist exclusively for the purpose of recording messages when one misses a call. The phone owner's recorded message usually says something similar to "Hello, this is John. I'm sorry I couldn't make it to the phone — please leave a message, and I'll get back to you as soon as I can." In some cases, such machines allow the phone owner to call his home number and remotely listen to the messages, but the functionality tends not to extend far beyond this.
Many companies, on the other hand, use automated answering machines to direct callers to the proper person or department. A person, upon calling a company's phone number, may get a message from an automated answering machine instructing him to press a certain number or symbol on his phone based on the reason he is calling. While an automated answering machine can be quite useful for such purposes, many find such systems to be overly complicated and confusing. One must often navigate complex and recursive phone menus before being directed to a human operator.
The widespread use of cell phones has somewhat reduced the demand for automated answering machines. Most cell phone service providers offer a voicemail service that offers all of the functionality of an automated answering machine without the need for an actual machine attached to the phone. Many people use cell phones as their primary telephones and, as such, do not require an automated answering machine. Regardless of this trend, new answering machines are still being made smaller, easier to use, and with more efficient storage and recording options.