Talk. A talk is something you give on stage or pre-recorded for the online conference. There will be a Q&A after either of these. The length can vary with the committee thinking either 30 or 60 minutes .. but you tell us.
Tutorial. A tutorial is short form presentation. This is not a workshop, but more of an introduction to a topic x for ~2 hours for a group of 20-40 people in a separate track/day of the online conference. A very light-weight hands-on learning could be involved in the tutorial. Tutorials will be hosted only during the on-line conference.
Workshop. A workshop is a full day (7 hours) of hands-on learning in a classroom setting.