The pipeline has stages: discovered (seen in a sitemap or link), crawled (fetched), rendered (JavaScript executed, if needed), indexed (stored), ranked (shown). A page can die at any stage — 'Discovered, currently not indexed' in Search Console is Google saying it found the page and chose not to bother, which is usually a quality verdict.
What earns indexing is what earns ranking, a step earlier: unique content worth keeping, internal links that show the page matters, a sitemap that says it changed. The diagnostics to know: Search Console's coverage report, site: queries, and request-indexing for the pages that deserve a nudge.
Related terms
XML sitemap
A machine-readable list of every URL worth indexing — last-modified dates included — so crawlers find all of it, fast.
robots.txt
A plain-text file at the site root telling crawlers what they may fetch — an instruction to machines, not a lock on a door.
SEO
Search engine optimization — making pages findable, indexable and worth ranking: technical health plus content people actually want.
The bench this belongs to
Web performanceA rebuild that loads on a phone on mobile data, in the country your customers are actually in. Core Web Vitals are the measurement, revenue is the point.
