The Match State setting in firewall rules refers to the state of the connections that the rule will allow, reject, or drop. In your case, the selected states are Established and Related. Here’s an explanation of the available options:

New

• Refers to a brand-new connection that is being initiated.
  • If selected, the rule applies to traffic attempting to establish a new connection.

Example: A device in the IoT network tries to start a new connection with a device in the LAN network.