As spotted in a recent entry on the YouTube feature experiments page, the automatic key concept detector uses machine learning to identify the most important topics in a video and then surface more information about those concepts in the form of images and short text snippets. This information can be used by viewers to learn more about the concepts or to follow along with the video.
This feature is currently being tested on a small set of English-language videos related to educational topics taught in schools (across subjects such as biology, physics, and chemistry). The experiment will take place on mobile only, for a limited number of people watching YouTube.
Creators have the option to opt out of the Key Concepts feature at the video level in YouTube Studio. To do this, go to Content> Details [for a particular video]> Select ‘Show More’> Uncheck ‘Allow automatic concepts’.
Not too long ago, Google also said that they were working to bring AI summarizer to YouTube. Basically, the AI auto-generated summaries will appear on watch and search pages, but the experiment is currently limited to a small number of English-language videos and a select group of viewers.