What is Robots.txt?
A plain-text file at the domain root telling compliant crawlers which paths they may fetch. It controls crawling, not indexing: blocked URLs can still be indexed by URL if linked.
Related terms
XML Sitemap
A machine-readable list of canonical URLs worth crawling, optionally with last-modified dates. One file holds 50,000 URLs or 50 MB uncompressed; larger sites segment by template or locale.
AI Bot Blocking
Using robots.txt (or edge rules) to stop AI crawlers from fetching a site. The tradeoff is direct: blocked content cannot be quoted or cited by the assistants doing the blocking.
Crawl Rate Limit
How fast a crawler is allowed to hit a server, set in Search Console or robots-adjacent controls. Lower it during fragile migrations; raise it when capacity allows faster discovery.
Technical SEO
The crawling, indexing, rendering, and performance work that lets search engines reach, understand, and serve your pages. It covers directives, architecture, speed, and structured data rather than words on the page.
Crawling
How search-engine bots discover pages by following links, sitemaps, and directives. If a URL is never crawled, it cannot be indexed no matter how good its content is.
Crawl Budget
The number of pages a search engine will crawl on a site in a given period, driven by server capacity and demand signals. Large or slow sites must spend it on indexable, valuable URLs.