SEO Glossary

SEO jargon explained in plain English, in a sentence or two.

Search engine optimization comes with a lot of vocabulary: canonical URLs, crawl budget, soft 404s, E-E-A-T, hreflang and a dozen kinds of links. This glossary explains each term in a sentence or two, without hype, so you can read an audit, a Search Console report or a developer's ticket and know what it means.

Definitions follow how Google itself describes things in Search Central where it does, and say so when a popular term isn't something Google uses. Third-party scores such as domain authority, for example, are estimates made by tool vendors, and keyword density is a measurement rather than a target. Type in the filter box to find a term, and follow the links to the tools that help with each part of the job.

Filter terms

71 entries

Terms A to Z

Term	Definition
301 redirect	A permanent redirect. Search engines move signals to the new URL and usually index it instead of the old one.
302 redirect	A temporary redirect. Google follows it but treats it as a weak signal that the target should replace the original.
404 error	The status a server returns for a page that doesn't exist. Normal and harmless for pages that really are gone.
Alt text	The alt attribute on an image: a text alternative for screen readers, also used by search engines to understand the image.
Anchor text	The clickable text of a link. It tells users and search engines what the linked page is about.
Backlink	A link to your site from another site. Links from relevant, trusted sites are one of the signals search engines use.
Black hat SEO	Tactics that break search engine spam policies, such as hidden text, cloaking or link schemes. They risk penalties.
Bounce rate	In analytics, the share of sessions with no engagement. Not something Google Search uses as a ranking signal.
Breadcrumb	A trail of links showing where a page sits in the site hierarchy, such as Home > Shoes > Running.
Canonical URL	The preferred URL among duplicate or near-duplicate pages, suggested with rel=canonical, redirects or sitemaps.
ccTLD	A country-code top-level domain such as .de or .fr. A strong signal that a site targets that country.
Cloaking	Showing search engines different content from what users see. A spam policy violation.
Core Web Vitals	Google's page experience metrics: Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness) and Cumulative Layout Shift (visual stability).
Crawl budget	How many URLs a search engine will crawl on a site in a given time. Mainly a concern for very large or fast-changing sites.
Crawler	A program that fetches pages by following links and sitemaps, such as Googlebot. Also called a bot or spider.
Crawling	Fetching pages so they can be processed. A crawled page isn't necessarily indexed.
CTR (click-through rate)	Clicks divided by impressions. Search Console reports it per query and page.
Cumulative Layout Shift (CLS)	A Core Web Vital measuring unexpected layout movement. 0.1 or less is good.
Disavow	A Search Console tool for asking Google to ignore specific backlinks. Rarely needed; Google ignores most spammy links on its own.
Domain authority	A third-party score that estimates a site's link strength. Google doesn't use any of these scores.
Duplicate content	The same or very similar content on several URLs. Usually handled with canonicals; not a penalty in itself.
E-E-A-T	Experience, Expertise, Authoritativeness and Trustworthiness: concepts from Google's quality rater guidelines, not a single ranking factor.
Featured snippet	An answer excerpt shown above or among the regular results. It's chosen automatically; there's no markup for it.
Googlebot	Google's main web crawler, which crawls as a smartphone for most sites.
H1	The top-level heading of a page. One clear H1 that matches the topic helps users and search engines.
Hreflang	An annotation that tells search engines about language or regional versions of a page.
HTTPS	HTTP over TLS encryption. A lightweight ranking signal and a requirement for many browser features.
Impressions	How often a page appeared in search results, whether or not anyone clicked.
Index	The search engine's database of pages it can show in results.
Indexing	Processing a crawled page and storing it in the index. Not every crawled page is indexed.
Interaction to Next Paint (INP)	A Core Web Vital measuring how quickly a page responds to clicks, taps and key presses. 200 ms or less is good.
Internal link	A link from one page to another on the same site. It helps discovery and shows which pages matter.
JSON-LD	JavaScript Object Notation for Linked Data: the structured data format Google recommends, in a script tag.
Keyword	A word or phrase people search for. Pages rank for topics and intent, not exact keyword counts.
Keyword cannibalization	Several pages on one site competing for the same query, which can split signals between them.
Keyword density	How often a word appears as a share of all words on a page. Not a ranking factor to aim for.
Keyword stuffing	Repeating keywords unnaturally to manipulate rankings. A spam policy violation.
Largest Contentful Paint (LCP)	A Core Web Vital measuring when the largest image or text block becomes visible. 2.5 seconds or less is good.
Link equity	Informal name for the value a link passes to the page it points to.
Local pack	The map and list of businesses shown for local searches, driven mainly by Google Business Profile data.
Long-tail keyword	A longer, more specific query with less volume and often clearer intent, such as 'waterproof trail running shoes for women'.
Meta description	A summary of the page in the head. Google may use it as the snippet; it isn't a ranking factor.
Meta robots	A meta tag with rules such as noindex or nosnippet that control indexing and display.
Mobile-first indexing	Google indexes and ranks the mobile version of a page's content.
Nofollow	A link attribute (rel="nofollow") or robots rule saying links shouldn't pass signals. Google treats the attribute as a hint.
Noindex	A robots rule that keeps a page out of search results. The crawler must be able to fetch the page to see it.
Open Graph	Meta tags (og:title, og:image...) that control how links look when shared on social networks and in chat apps.
Orphan page	A page no other page on the site links to, so crawlers and users struggle to find it.
Page speed	How quickly a page loads and responds. Measured for users by the Core Web Vitals.
Pagination	Splitting a long list across numbered pages. Each page should have its own URL and link to the others.
People Also Ask	A box of related questions with expandable answers in Google results.
Redirect chain	Several redirects in a row (A to B to C). Point links and redirects straight at the final URL.
Rel=sponsored	A link attribute for paid or sponsored links, required by Google's link spam policies.
Rel=ugc	A link attribute for links in user-generated content such as comments and forum posts.
Rich result	A search result with extra features, such as stars, prices or images, often enabled by structured data.
Robots.txt	A file at the site root that tells crawlers which paths they may crawl. It doesn't remove pages from the index.
Schema.org	The shared vocabulary for structured data, maintained by the major search engines.
Search Console	Google's free service for site owners: indexing status, queries, Core Web Vitals and messages from Google.
Search intent	What someone wants when they type a query: to learn, to find a site, to buy or to compare.
SERP	Search engine results page: everything shown for a query, including ads, organic results and other features.
Sitemap	An XML file listing the URLs you want crawled, optionally with their last modification dates.
Slug	The readable part of a URL that identifies a page, such as running-shoes in /blog/running-shoes.
Snippet	The description text under a result's title, taken from the meta description or the page itself.
Soft 404	A page that says it doesn't exist (or is empty) but returns 200. Return a real 404 or 410 instead.
Structured data	Machine-readable information about a page, usually JSON-LD using schema.org, that can enable rich results.
Thin content	Pages with little original value, such as scraped text or near-empty doorway pages.
Title link	Google's name for the clickable title of a search result, usually taken from the title tag.
UTM parameters	Query string tags (utm_source, utm_medium, utm_campaign...) that tell analytics tools where a visit came from.
White hat SEO	Improving rankings within search engine guidelines: helpful content, good technical setup and earned links.
X-Robots-Tag	An HTTP header carrying robots rules, useful for PDFs, images and other non-HTML files.
XML sitemap	See sitemap. The standard format is defined at sitemaps.org; one file holds up to 50,000 URLs or 50 MB uncompressed.

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