A seat map is a visual seating chart you build once and reuse. When you attach a map to an event, the event gets its own copy, and later edits on either side stay independent - changing the event's layout never touches your library template, and updating the template only reaches events if you choose to roll it out.
Build maps in your library, then attach one to an event.
Use a map when bookings should be tied to specific seats, or when you want different prices across parts of the room (zones).
Maps are drafts until you publish them - an event can only go live on a published chart.
The "Not linked" filter shows maps not yet attached to any event.
To get building, see Build a seat map.