To use picture-in-picture, or PIP, on a typical television, press the PIP button on the remote control, and select the second source to display. Video from this second source appears in a small box in the corner of the screen. Common PIP functions are swapping the second picture and the main picture, changing the size of the second picture, changing the picture's location, changing the channel of the second picture and swapping the sound source between pictures.
PIP requires two independent tuners or signal sources, one for each picture. Some televisions have a second tuner built in, but a single-tuner PIP TV requires a second external signal source. This input may come from a video playback device, such as a VCR, DVD player, digital video recorder or computer, a live signal from a second tuner or cable box, or a streaming device such as a Roku or Apple TV. Certain televisions may allow PIP playback from two video sources at the same time, for example from a DVD player and a computer.
There are other less common but similar television functions. Picture-and-text, or PAT, displays a television program on one half of the screen and a teletext page on the other. Picture-by-picture or picture-and-picture, displays two programs side-by-side on the screen. The sound from one program is sent to the speakers, and the sound from the second is played over headphones.