Manager node gossip vs database node gossip

Acc to http://docs.geteventstore.com/server/4.0.0/cluster-with-manager-nodes/, manager nodes

  • They communicate with other manager nodes in order to determine overall cluster state, and relay that information to the database nodes under management."
  1. How is this information different from what database nodes gossip with each other?

  2. Is it necessary to configure both database and manager nodes to gossip with one another?