Picture-in-picture (PiP) mode is a feature offered by numerous television receivers and devices. In this mode, one program (or channel) is displayed on the full TV screen and at the same time, one or more than one programs are displayed in the inset windows. But the sound that you will on screen is usually from the mail program.
Also Check: How to Check Which App Support Picture-in-Picture mode on Android 8.0 Oreo
Now let’s understand how the picture-in-picture mechanism actually works. Picture-in-picture requires two independent tuners (or signal sources) for its functioning to supply both (the large and the small) pictures. Two-tuner Picture-in-Picture TVs have another built in tuner, but a single-tuner Picture-in-Picture TV requires an external signal source. The external signal source may be an external tuner, DVD player, Videocassette recorder, or a cable box. This mode can be used when you want to keep watching something before waiting for a program to start or during commercials.

In Android 7.0 and Android TV, users are able to watch multiple videos together while navigating within or between apps via the Picture-in-Picture (PIP) mode. The mode lets users run a video or movie in the pinned window while another video or movie/activity continues in the background. The mode enables users to multitask which in turn increases one’s productivity.