The ticket Level # of Attendees Per Purchase indicates how many tickets/attendees are allowed when a single quantity of the ticket Level is selected.
NOTE: Refer to this article on setting the value to zero, Zero Attendee Event Levels.
Workspace > Events > Event Pages, Event Setup step, Levels tab
The event purchaser/registrant enters the quantity on the event webpage, and the software multiples that by the # of Attendees Per Purchase.
Event webpage, Quantity (Qty.) and Attendees
Examples of setting # of Attendees Per Purchase to a value greater than one (1).
For events that have sponsor levels or couple tickets, the # of Attendees Per Purchase could be (for example) 4 and 2, respectively.
When a sponsor selects 1 quantity, they are getting 4 tickets (attendees). When a couple selects 1 quantity, they are getting 2 tickets (attendees).
In general, the ticket Level is set to 1, as 1 quantity = 1 attendee/ticket.