What is site map (discovery)?
Mapping discovers what URLs a site exposes without reading the pages behind them. It combines declared sitemaps, robots.txt directives and a shallow scan of links, returns the list with per-source counts and a truncation flag, and costs a flat fee whatever the site’s size.
Why it matters
It is the cheap look that makes the expensive read deliberate. Filtering a map is how you decide what a crawl is allowed to touch — and it answers "does this site even have the section I think it has" for the price of one call.