Length (in minutes) is total length including (but not limited to) presentation, Q&A, short breaks (for workshops) and even unforeseen problems by any causes.
Talk is the format which a speaker presenting to audiences (mainly listen) in a session. 30-minute is regular length, and 10-minute is shorter format for new speakers or quick sharing.
Workshop (in a classroom) is the format which a speaker teach on a topic which audiences can follow to do on their laptops at the same time (interactive) in a session. Please include short breaks if the proposed workshop is longer than 45 minutes.
Classroom Activity is the free style format which provide more feasibility, it can serve for 30 minutes or up to a full day activiity (Approx. 11:30-16:30), it can be presentations, workshops, tutorials, hackathons, etc.
For 5-minute Lightning Talk, please select "Lightning Talk" in above Topic Type / Track.