An answering machine (other names are answerphone, ansaphone, ansafone and Telephone Answering Device (TAD)) is a machine. It is attached to a telephone line. If the phone is not answered after a few rings, it will play a message to the caller. The caller can then leave a message (after a sound that has become known as "the beep"). It is different form voicemail which is based in the network. Answering machines are installed at home (or at the office).