When the Campaign Guardian is enabled for pages, only authorized users will have access to protected pages. The Guardian is universal to a specific campaign i.e. as long as your users have access to one protected page, they will have access to all the other pages protected by that specific Campaign Guardian.
This is very useful for launch sequences when you want people to opt in to a list, but not have them need to opt in on every page of that launch. The universal guardian will remember that they have opted in previously and will show them the next launch page without interruption.
TIP: When a brand new campaign is setup, the Campaign Guardian is disabled for each page of the Campaign by default. To activate the Guardian for specific pages of the campaign simply follow the steps in the article below.