Peer to Peer Networking: A system of forming networks between computers which allows individuals to share data, from their hard drives and other storage devices, between users on the same network. Internet peer to peer software is frequently used to share music and video files.
PSTN (Public Switched Telephone Network): Refers to an every-day local, national and international voice oriented switched telephone network.
PTO (Public Telecommunications Operator): An operator who provides a PSTN service.
PVR (Personal Video Recorder): feature integrated in some set top boxes enabling subscribers to record, fast forward, rewind programming. The term DVR (Digital Video Recorder) is increasingly prevalent