Every Personalization campaign has to have the pages it should run on setup before you start creating your variations. These pages are the ones where your campaign is going to run. You can either add a single page either multiple pages dynamically by using rules.
A distinctive name for your page so you can later easily understand which page is which. Good examples would be Pricing, Product page, Homepage
As mentioned above every page can be configured to actually include a single page or multiple pages. This works best for dynamic pages which are different by have a lot in common like product or collection pages.
When using the single page type you only have to specify the page that you want personalize by specifying the whole URL in the Page URL field.
When using the advanced page type you can make the page actually match more pages on your website. This would be done be specifying the rules that a page should satisfy in order to match.
Besides specifying the rules you should also specify a sample URL where the website editing will take place.