Picture-in-picture keeps a main view visible while layering a smaller view over it. It is useful for showing two kinds of information at once, such as a presenter and a screen recording.
Place a secondary video layer over the main view and choose its size and position. In the demo, a small window with a presenter silhouette moves slowly between the corners.
PIP overlays one view; split screen assigns each view its own area. Keep the inset away from important controls and captions, and make it large enough to remain legible.
When to use
Use it to show two threads together, such as a screen demonstration and presenter reaction. Check that the inset does not cover an important control.