SEO glossary: 77 SEO terms explained

SEO terms A to Z

301 redirect

A permanent redirect from one URL to another that passes most ranking signals to the new URL.

302 redirect

A temporary redirect. Use 301 for permanent moves.

404 error

A "page not found" response. Fine for pages that are truly gone; redirect them if a close replacement exists.

AEO (answer engine optimisation)

Structuring content so it is chosen as the direct answer in featured snippets, voice assistants and AI answers. See AI SEO.

AI Overviews

Google's AI-generated summaries shown at the top of some search results, with links to source pages.

Algorithm

The system of rules and signals a search engine uses to rank results. Google updates its algorithms thousands of times a year, with larger "core updates" a few times a year.

Alt text

A text description of an image in HTML, used by screen readers and search engines.

Anchor text

The clickable words in a link.

Backlink

A link from another website to yours. See backlinks.

Black hat SEO

Tactics that break search engine guidelines, such as link schemes, cloaking and keyword stuffing.

Bounce rate

The share of visits that leave without interacting. In GA4 the related metric is engagement rate.

Breadcrumbs

A navigation trail (Home › Guides › Page) that helps users and search engines understand site structure.

Canonical tag

An HTML tag naming the preferred URL when similar or duplicate pages exist.

Citation

An online mention of a business's name, address and phone number, important for local SEO.

Cloaking

Showing search engines different content from what users see. A spam tactic.

Core Web Vitals

Google's page experience metrics: LCP (loading), INP (responsiveness) and CLS (visual stability).

Crawl budget

How many URLs Google will crawl on a site in a given period. Mostly relevant for large sites.

Crawler (spider, bot)

A program such as Googlebot that discovers and reads web pages.

CTR (click-through rate)

Clicks divided by impressions: the share of searchers who click your result.

Dofollow link

A normal link that can pass ranking value (there is no actual "dofollow" attribute).

Domain Authority (DA)

A Moz metric (1 to 100) estimating a site's ranking strength from its backlinks. Not used by Google.

Domain Rating (DR)

An Ahrefs metric (0 to 100) measuring the strength of a site's backlink profile. Not used by Google.

Doorway pages

Many near-identical pages created to rank for slight keyword variations. Treated as spam.

Duplicate content

The same or very similar content on more than one URL, which splits ranking signals.

E-E-A-T

Experience, Expertise, Authoritativeness and Trustworthiness: qualities Google's quality raters look for.

Entity

A distinct, well-defined thing (a person, place, business or concept) that Google understands and connects to others in its Knowledge Graph.

Featured snippet

A highlighted answer box shown at the top of some Google results, quoting a web page.

GEO (generative engine optimisation)

Optimising content so AI tools such as ChatGPT and Google AI Overviews cite it.

Google Business Profile

Google's free business listing that appears in Maps and local results (formerly Google My Business).

Google Search Console

Google's free tool for monitoring search performance, indexing and errors.

Googlebot

Google's web crawler.

Grey hat SEO

Tactics in a grey area between guidelines-compliant and manipulative. Risky over time.

H1 tag

The main heading of a page.

Hreflang

A tag telling Google which language or regional version of a page to show.

Impressions

The number of times a page appears in search results.

Index / indexing

Google's database of pages, and the process of adding pages to it.

Internal link

A link from one page to another on the same website.

Keyword

A word or phrase people type into a search engine. See keyword research.

Keyword cannibalisation

Several pages on one site competing for the same keyword.

Keyword density

How often a keyword appears relative to total words. Google has no target density.

Keyword stuffing

Overusing keywords unnaturally. Against Google's spam policies.

Knowledge panel

An information box about an entity (business, person, brand) shown on the right of Google results on desktop.

Link building

Earning links from other websites to yours.

Local pack (map pack)

The group of Google Maps business listings shown for local searches.

Long-tail keyword

A longer, more specific search phrase with lower volume and clearer intent.

Manual action

A penalty applied by a human reviewer at Google for breaking spam policies, shown in Search Console.

Meta description

An HTML tag summarising a page, often shown under the title in search results.

Meta robots tag

An HTML tag controlling indexing and link following, such as noindex or nofollow.

Mobile-first indexing

Google uses the mobile version of a page for indexing and ranking.

NAP

Name, Address, Phone number: business details that should be consistent everywhere online.

Nofollow

A link attribute telling search engines not to pass ranking value. Related attributes: sponsored and ugc.

Noindex

A directive telling search engines not to include a page in their index.

Off-page SEO

SEO activities outside your website: backlinks, mentions, reviews.

On-page SEO

Optimising content and HTML on your own pages. See on-page SEO.

Organic traffic

Visitors who arrive from unpaid search results.

Orphan page

A page with no internal links pointing to it, making it hard for Google to find.

Page speed

How fast a page loads and becomes usable.

PageRank

Google's original algorithm for measuring a page's importance from links. Still used internally in evolved form.

People also ask (PAA)

A Google results box listing related questions with expandable answers.

Pillar page

A broad page on a core topic linked to more detailed cluster pages.

Ranking factor

A signal a search engine uses to order results, such as relevance, links or page experience.

Rich results (rich snippets)

Enhanced search results showing extras such as stars, prices, FAQs or images, often enabled by schema markup.

robots.txt

A file telling crawlers which parts of a site not to crawl.

Schema markup (structured data)

Code that describes content to search engines in a standard vocabulary (schema.org).

Search intent

The goal behind a search: informational, commercial, transactional or navigational.

SEM

Search engine marketing, covering SEO and paid search (often used to mean paid search only).

SEO

Search engine optimisation: improving a site to rank higher in unpaid search results. See what is SEO.

SERP

Search engine results page: the page of results Google shows for a search.

Sitemap (XML)

A file listing the URLs you want search engines to index.

Slug

The part of a URL that identifies a specific page, such as "seo-glossary".

Technical SEO

Optimising crawling, indexing, speed and site infrastructure. See technical SEO.

Thin content

Pages with little original or useful content.

Title tag

The HTML title of a page, usually shown as the clickable headline in search results.

UR (URL Rating)

An Ahrefs metric estimating the strength of a single page's backlink profile.

White hat SEO

SEO that follows search engine guidelines and focuses on users.

White label SEO

SEO work done by one company and resold by another (such as a web design or marketing agency) under its own brand.

YMYL

"Your Money or Your Life": topics such as health, finance and legal where Google applies higher quality standards.

Questions answered