Online means that you will follow the full course from your own location via videochat.
Offline/hybrid means that you follow the course in the classroom (with 1,5m distance) and that you will participate online from your own location only when necessary (in case you have a cold and need to stay home while getting tested for COVID-19, or in case of government restrictions to classroom gatherings).
When filling in an application form, you may state your preference for online or offline/hybrid classes.