A landline is a telephone connection that uses metal wires from the owner's premises also referred to as: POTS, Twisted pair, telephone line or public switched telephone network (PSTN).
A corded landline telephone made by Siemens from c. 1997
Total landline vs. mobile phones in Africa (1998–2008)
Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for voice calls for the delivery of voice communication sessions over Internet Protocol (IP) networks, such as the Internet.
Asterisk-based PBX for small business