There are times when you don't want to notify requester on resolving a ticket. For example when requester reopens an already solved ticket to say "thank you". The native trigger that sends a notification to requester about a solved request is called "Notify requester of solved request" and that trigger contains the condition "Comment - Public comment".

That means that by disabling "This is a public comment" when updating the ticket, the trigger is not set off and requester won't receive (another) notification saying that the ticket is solved. You can add similar condition checks on all triggers to avoid unnecessary notifications.