Page level refers to the level of a page relative to the site's index URL.
The index URL is the URL where the crawler starts to scan your website. It is referred to as on Page level 1. The index URL is normally but not always the homepage of your website.
Page level example:
For the Siteimprove website, the index URL configured in the platform is https://siteimprove.com.
The index URL is on Page level 1,
A page linked to from level 1 is on Page level 2,
A page linked to from level 2 is on Page level 3,
The Page Inspector shows the Page levels and the shortest path to a page from the index page. You can access the Page Inspector by clicking on the icon to the right a page title within the platform.
Note: If the index URL configured was www.siteimprove.com/about-us/ then that page would be Page level 1 and linked pages would level 2 and so on.