chrome://webrtc-internals is an internal Chrome tab that holds statistics about ongoing WebRTC sessions.
It can be used to debug the flow of WebRTC sessions to determine issues during development or deployment.
Check this series of articles that explain in detail what is inside webrtc-internals and how to use it.
WebRTC Glossary is a collaborative space where users can learn more about WebRTC related terms. Anyone can also modify or add new terms to this glossary, but it requires registration to the site first.