The Event Capacity will limit the number of customers that can register for a specific event. This is not to be confused with the roster Min and Max.
Once the capacity is reached, the Dash Online experience will prevent the customer from selecting that event/day. Registration would remain open for other events in the series
This setting can be established either on the Edit Camp page for the event.
Or it can also be saved for all events when creating the series from the Camp scheduler.