Google Search Console (GSC), formally known as Webmaster Tools, is a free resource provided by Google. It contains useful and actionable data about how Google is interpreting the website such that webmasters can implement fixes and track performance over time.
The GSC Coverage Report, in tandem with the URL Inspection report, are important tools to understand how Google interprets your site’s pages and, as a result, the health of the site at large. The coverage report breaks your pages down into 4 sections; Valid, Warnings, Error and Excluded, the foremost can be ignored for the purposes of this discussion.
Valid with Warnings
The pages are generally fine and would be in the Valid category, however, there is something stopping Google from Indexing the page.
Pages in this category are generally related to technical errors, such as server response errors (5xx errors), broken pages (404 or soft 404) or even pages just marked up as Crawl anomaly, which appears to be a catch-all for a wealth of other errors.
The Excluded section of the Coverage Report is reasonably complex as it reports on a variety of issues, some of which are issues and some of which are reported as a result of intentional actions the Site owner might have taken. For example, a Not found (404) report may be pages that have been incorrectly linked to (so should be fixed) or pages the Site owner has intentionally removed, in which case they will remain in this state for 90 or more days before GSC forgets about them.