Cohort
A cohort is a group of students who take a course at the same time, with shared start and end dates. They move together, unlike on-demand formats where everyone begins whenever they like.
Cohort formats tend to show far higher completion rates, because they add social pressure, a calendar and live support.
The cost is that they do not scale on their own: every run takes your time. Many schools combine both, with an on-demand course as the entry point and live cohorts as a higher-priced product.