nostr:nevent1qqs96uv8xjz635kr89ar5v34ctta9g7gmuqma9vtptck8kulclxc6dgpz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsygp6jxvxg8lfnznc2lydnlr7ss96zws7l0m9yyykeveunqnuyxhvlgpsgqqqqqqs8pqx0a

Every coordinator is an independent server hosting their own orders, and if you want to know the orders hosted by coordinator X you need to do a call to its API (actually 2). There are 4 active coordinators today, but nothing stops that number to be 100. You can see the API method doesn't scale up if you want to see the global orders book.

With nostr, every coordinator runs its own relay on a way that continuously synchronizes with the rest, so all relays hosts all active orders. On this sceneraio a client only requires to connect to 2-3 random coordinator relays to have access to the entire global book.