Crawling

Crawling is the process by which a search engine's automated bot (a crawler) discovers pages by following links, in order to read and evaluate them for indexing.

Crawling and indexing are two separate steps that get conflated constantly — a page can be crawled without being indexed (Google visited it but decided not to add it to the index) or, less commonly, indexed based on other signals without a full crawl. "Google crawled my site" is not the same claim as "Google indexed my pages," and Search Console reports both states separately for exactly this reason.