What data is saved locally when using query?

Hello i’m a flutter developer but this is my first time working with mongoDB database. I would like to ask if the code below will save locally all of the Rule objects or only the ones with the corresponding user id. Thanks in advance.

_realm = Realm(Configuration.flexibleSync(user, [Rule.schema]));
_realm.subscriptions.update((mutableSubscriptions) {
  mutableSubscriptions.add(_realm.query<Rule>('userId == \$0', [user.id]));