A historical Search Console report name associated with URL indexing status; the current comparable report is Page indexing.
A guide referring to the Coverage report is usually discussing which URLs Google indexed and why other URLs were not indexed. The current Page indexing report is the appropriate starting point for that task, while individual URLs can be investigated with URL Inspection.
An excluded or not-indexed URL is not automatically an error. A redirect, an intentionally blocked page, or a duplicate represented by a canonical can be expected. The business question is whether the right useful pages are eligible and appearing, not whether every discovered URL is indexed.
Use report groups to find patterns and inspect representative examples. If a template change affects a hundred service pages, grouping can reveal the shared issue faster than treating each URL as an unrelated incident. Reporting also reflects data collection rather than every live change instantly.
Takeaway: Prioritize important pages that should be indexed; do not try to make every excluded URL turn green.
Example
A store sees many alternate product-filter URLs outside the index. The primary product URLs are indexed correctly, so it separates expected duplicates from genuinely missing product pages.
What to check
Compare the report date, sitemap membership and individual inspection before interpreting a count change. An indexing report is not a ranking report.
For more detail, see Google Page indexing report.