Microsoft Teams: How is a "Town hall" different from a "Meeting" and "Webinar"?
Essentially, A TOWN HALL has capacity for 10,000 attendees (20,000 for premium users). There is also no registration needed for a Town Hall. Additional differences: There is NO content sharing and interaction in Town Halls. There is only a "Q&A" option. Attendees do NOT have the mic and camera option. No end to end encryption in Town Halls.
https://learn.microsoft.com/en-us/microsoftteams/overview-meetings-webinars-town-halls