Picture-in-picture (PiP) is a feature that allows users to watch a video in a small window while simultaneously using other applications on their device. This small window can be moved around the screen, enabling multitasking without interrupting the video playback. PiP is commonly used in various devices, including smartphones, tablets, and smart TVs. It enhances the viewing experience by allowing users to keep an eye on their favorite shows or video calls while browsing the internet or working on other tasks.