Basic and Advanced Tracks
This course is offered in two tracks. The advanced track is intended to be an undergraduate or early graduate level course, and you should plan on spending around ten hours a week or more on it. It will involve weekly homework assignments as well as a midterm exam and a final exam. In order to receive a statement of accomplishment for the advanced track you must take both the midterm and the final exam.

The basic track is for people interested in the material but who do not have time or would prefer not to do homework assignments and exams. You will be able to view the same lectures as the advanced track, and will have access to the homework assignments and exams after they have been completed by students in the advanced track but will not be scored on them. In order to receive a statement of accomplishment for the basic track you must stay active and continue to view material throughout the course.

https://www.ai-class.com/overview

Em conferências é comum que hajam palestras ou cursos simultâneos divididos em trilhas. Há conferências em que você pode escolher na hora, há outras em que é preciso se registrar antes.

Isso vale também para a sua outra pergunta.