SEO & Indexing Glossary

Indexing terms, in plain English

Every term you'll meet in Search Console and indexing — what it means, why it matters, and how to check it.

The indexing & crawling glossary: every term you'll meet in Search Console and SEO — what it means, why it matters for getting indexed, and how to check it. Plain-English definitions, grouped by where they fit in the crawl → index → rank pipeline.

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Crawling & discovery

Web crawlerAn automated bot that discovers and fetches web pages by following links.GooglebotGoogle's web crawler that discovers and fetches your pages.Crawl budgetHow many pages Googlebot is willing to crawl on your site in a given time.Internal linkingLinks from your own pages to other pages on your site.Orphan pageA page with no internal links pointing to it.XML SitemapA machine-readable list of your indexable URLs for search engines.

Indexing & APIs

Google Indexing APIGoogle's notification API for officially supported JobPosting and BroadcastEvent pages.IndexNowOpen protocol to quickly notify Bing, Yandex & others of changes.URL Inspection APIProgrammatic access to a URL's index status in Search Console.Page indexing reportThe Search Console report showing which pages are indexed and why not.SERPSearch Engine Results Page — where indexed pages appear.Structured data (schema)Tagged markup that helps Google understand a page's content.

Directives & technical

robots.txtA file that tells crawlers which paths they may or may not crawl.noindexA directive telling search engines NOT to index a page.Canonical tagTells Google which URL is the “master” version of duplicate or similar pages.

Indexing problems

Crawled – currently not indexedGoogle fetched the page but actively chose not to index it.Discovered – currently not indexedGoogle knows the URL exists but hasn't crawled it yet.DeindexedWhen pages once in Google's index get removed from it.Thin contentPages with little unique value for the user.Duplicate contentMultiple URLs with the same or very similar content.
20 terms · updated June 2026
Canonical tag
Tells Google which URL is the “master” version of duplicate or similar pages.
Crawl budget
How many pages Googlebot is willing to crawl on your site in a given time.
Crawled – currently not indexed
Google fetched the page but actively chose not to index it.
Discovered – currently not indexed
Google knows the URL exists but hasn't crawled it yet.
Duplicate content
Multiple URLs with the same or very similar content.
Googlebot
Google's web crawler that discovers and fetches your pages.
Google Indexing API
Google's notification API for officially supported JobPosting and BroadcastEvent pages.
IndexNow
Open protocol to quickly notify Bing, Yandex & others of changes.
Page indexing report
The Search Console report showing which pages are indexed and why not.
Internal linking
Links from your own pages to other pages on your site.
noindex
A directive telling search engines NOT to index a page.
Orphan page
A page with no internal links pointing to it.
robots.txt
A file that tells crawlers which paths they may or may not crawl.
SERP
Search Engine Results Page — where indexed pages appear.
XML Sitemap
A machine-readable list of your indexable URLs for search engines.
Structured data (schema)
Tagged markup that helps Google understand a page's content.
Thin content
Pages with little unique value for the user.
URL Inspection API
Programmatic access to a URL's index status in Search Console.
Web crawler
An automated bot that discovers and fetches web pages by following links.
Deindexed
When pages once in Google's index get removed from it.
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Frequently asked questions

What's the difference between crawling and indexing?

Crawling is a bot fetching a page; indexing is the separate decision to store it in the searchable index. A page can be crawled but not indexed.

Why isn't my page indexed?

Most often a blocker (noindex, robots.txt, wrong canonical) or a quality signal (thin / duplicate content). The Page indexing report names the reason; fix that, then resubmit.

Know the term — now fix the page.

Check whether your URL is indexed, then review an eligible workflow using applicable signals from the 8-channel layer. Start with 200 one-time trial check credits.

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