The SEO vocabulary, defined plainly

29 terms that turn up in search reports and site audits, each answered in a sentence before it is explained. No jargon used to define jargon.

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301 redirect: A 301 redirect tells browsers and search engines a URL has moved permanently, and passes that URL's ranking signals to the new address; a 302 says the move is temporary and leaves the signals where they were.

Alt text: Alt text is the written description in an image's `alt` attribute, read aloud by screen readers and shown when the image fails to load.
Anchor text: Anchor text is the clickable wording of a link — the words a reader sees and a search engine reads as a description of where the link goes.

Backlink in depth: A link from another site to yours, and why two are never equal.
Bounce rate: Bounce rate is the percentage of sessions in which someone arrived, did nothing measurable, and left without a second interaction.

Canonical tag: A canonical tag is a `<link rel="canonical">` in a page's head that names which URL should be treated as the authoritative version of that content.
CDN: A CDN, or content delivery network, is a set of servers spread across the world that hold copies of your files and serve each visitor from a nearby one.
Click-through rate: Click-through rate is the share of people who clicked your result out of everyone who saw it — clicks divided by impressions.
Core Web Vitals: Core Web Vitals are the three metrics Google uses to measure page experience: how fast the main content appears, how quickly the page responds to input, and how much the layout shifts while loading.

Disavow: A disavow file is a list of domains or URLs you upload to Search Console to ask Google to ignore the links they point at your site.
Domain authority in depth: A third-party score, not a Google metric. What it can tell you.

E-E-A-T: E-E-A-T stands for Experience, Expertise, Authoritativeness and Trustworthiness — the qualities Google's human quality raters are asked to judge content against.

Favicon: A favicon is the small square icon that represents a site in browser tabs, bookmarks and, on mobile, next to your result in Google.

hreflang: hreflang is an annotation that tells search engines which language and region a page is written for, and which other URLs are its equivalents in other languages.
HTTP status codes: An HTTP status code is the three-digit number a server returns with every response, telling the client whether the request worked and what to do next.

Impressions: In Google Search Console, an impression is recorded each time a link to your site appears in a set of results a searcher has seen.
Internal linking: Internal linking is the practice of linking between pages on your own site, which is how crawlers discover them and how ranking signal moves around.

Knowledge panel: A knowledge panel is the box of facts Google shows beside or above results when it recognises the query as being about a known entity — a company, person, place or product.

Link building: Link building is the practice of getting other websites to link to yours, in order to improve how search engines judge your pages.

Meta description: A meta description is a short summary in a page's HTML that search engines may use as the snippet beneath its title in results.

Open Graph: Open Graph is a set of meta tags that tell social platforms and messaging apps what title, description and image to show when someone shares your URL.

Page speed: Page speed is how quickly a page becomes visible and usable for a real visitor, measured in a set of timings rather than as a single number.

robots.txt: robots.txt is a text file at the root of a domain that tells well-behaved crawlers which paths they may and may not request.

Schema markup: Schema markup is structured data added to a page — usually as JSON-LD — that states in machine-readable terms what the page is about.
SERP: A SERP is a search engine results page — the page Google returns for one query, including the organic results, the ads and every panel and box around them.
Sitemap: A sitemap is a file listing the URLs on your site that you want search engines to know about, usually as XML at a fixed address like /sitemap.xml.
Subdomain: A subdomain is a prefix added to a domain — the `blog` in `blog.example.com` — which can point anywhere and be run as a separate site.

Title tag: The title tag is the HTML element that gives a page its name — shown as the clickable headline in search results and as the browser tab label.

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