OBS Studio is free software that allows you to:
- Overlay a mix of video, images and screen captures
- Can create a “virtual camera” that other programs, like Google Meet or Canvas will view as a camera.
- Supports green screen effects
- and more
With OBS, you can create some very smooth workflows that look very professional. Here is an example of using OBS Studio for video comments for students.
You don’t NEED OBS Studio, but it can make your webinars and videos more professional and can also do some neat tricks like the one I demonstrate above that aren’t possible any other way. Here is a solid introduction to OBS-Studio.