A landline phone, unlike a mobile phone, uses a physical wire system for transmission. Landline phones are found in most buildings and can be connected to a single line or multiple lines. In a typical household setting, most people will have a single telephone line. Some homes or offices will have a single telephone line, connected to several outlets so when a call comes in you can pick the call upon any of them. Office phones will sometimes have more than one line allowing two or more calls to be dealt with at the same time enabling employees to place calls on hold, dial internal or external numbers and return to the line. Landline phones usually come with a variety of features like answering machine, speakerphone, nuisance call blocker, call recording, phonebook, conference calling, call waiting and caller ID and alarm.