SEO Glossary A–Z

An A–Z glossary of link building and SEO terms, defined in plain English.

Every link building and SEO term we use in proposals, audits and reports, defined in plain English and listed A to Z. There are 171 entries; use the index to jump to a letter.

#

301 Redirect: A permanent redirect. It sends visitors and search engines to a new URL and passes the great majority of ranking signals along with them.
302 Redirect: A temporary redirect. Use it only when the original URL will genuinely return; leaving one in place for months invites indexing confusion.
404 Error: The server response for a page that does not exist. A few are normal; hundreds of linked 404s waste crawl budget and lose link value.
410 Gone: A stronger signal than 404 that a page was deliberately removed and will not return, so search engines drop it faster.

A

Above the Fold: The part of a page visible before scrolling. What sits here disproportionately drives engagement and conversion.
Accelerated Mobile Pages: A stripped-back HTML framework for fast mobile pages. No longer required for top stories placement, and rarely worth new investment.
AI Overview: A generated summary Google places above traditional results. Being cited inside one depends on clear, quotable, well-sourced content.
Alt Text: A written description of an image used by screen readers and image search. Describe the image, do not stuff keywords.
Anchor Text: The clickable words in a link. They tell search engines what the destination page is about.
API: An interface that lets software pull data from another service, such as fetching rankings or backlinks programmatically.
Authority: A loose term for how much trust a site has earned, usually estimated from the quality and quantity of its backlinks.

B

Backlink: A link from another website to yours. Still one of the strongest ranking signals when it is editorially given.
Black Hat SEO: Tactics that break search engine guidelines, private blog networks, cloaking, hacked links. Fast gains, high risk of penalties.
Blogger Outreach: Contacting real site owners to earn a mention or link based on the value of your content or product.
Bounce Rate: The share of sessions with no further interaction. Useful as a trend, not as a ranking factor.
Branded Anchor: Anchor text that uses your brand name. It is the safest and most natural anchor type in any healthy link profile.
Breadcrumb: A navigational trail showing the page hierarchy. Helps users and can appear in search results.
Broken Link: A link pointing to a URL that returns an error. Fixing them recovers lost link equity and improves user experience.
Broken Link Building: Finding dead pages other sites link to and offering your working resource as a replacement.

C

Cache: A stored copy of a page or asset served to speed up delivery.
Cannibalisation: Two of your own pages competing for one query, so neither builds enough authority to win it.
Canonical Tag: Markup that declares the preferred version of duplicate or near-duplicate pages.
Citation: A mention of your business name, address and phone number on a directory or local site. Consistency matters more than volume.
Click-Through Rate: Clicks divided by impressions. Titles, descriptions and rich results all move it.
Cloaking: Showing search engines different content than users see. A direct guideline violation.
Co-Citation: Being mentioned alongside the same brands or topics repeatedly, which helps establish what you are associated with.
Content Audit: A systematic review of every page to decide what to keep, improve, merge or remove.
Content Decay: The gradual traffic loss an unmaintained page suffers as competitors publish fresher, deeper coverage.
Content Gap: Topics or queries competitors cover and you do not, usually the fastest route to new traffic.
Content Hub: A pillar page plus tightly linked supporting articles that together demonstrate depth on one subject.
Contextual Link: A link placed inside body copy rather than in a footer, sidebar or author bio. Worth considerably more.
Conversion Rate: The share of visitors who complete the action you care about, such as a form submission or purchase.
Core Update: A broad change to Google's ranking systems. Recoveries come from genuine quality improvements, not quick tweaks.
Core Web Vitals: Google's measurements of loading (LCP), interaction responsiveness (INP) and layout stability (CLS).
Crawl Budget: How much of your site a search engine will fetch in a given period. Matters mostly on large sites.
Crawl Depth: How many clicks from the homepage a page sits. Important pages should be within three.
Crawl Error: A failure a crawler hit when requesting a URL, server error, timeout or blocked resource.
Crawler: A bot that follows links to discover and download pages, such as Googlebot or Bingbot.
CSS: The styling layer of a page. Blocking it from crawlers stops Google rendering the page as users see it.
Cumulative Layout Shift: A Core Web Vital measuring how much the layout jumps while loading. Reserve space for images and ads.

D

Deindexing: A page or site being removed from the search index, whether deliberately or as a consequence of a penalty.
Digital PR: Earning coverage and links in the press through stories, data and expert commentary.
Directory Link: A listing in a categorised index. Valuable only from genuine, curated, industry-relevant directories.
Disavow File: A list of domains you ask Google to ignore. Rarely needed now, and easy to misuse.
Dofollow: A normal link with no rel attribute limiting endorsement, so it can pass ranking signals.
DOM: The rendered structure of a page after HTML, CSS and JavaScript have been processed. What Google actually indexes.
Domain Authority: Moz's 0–100 estimate of a domain's ranking strength. A comparative tool, not a Google metric.
Domain Rating: Ahrefs' 0–100 estimate of backlink profile strength. Useful for screening prospects.
Doorway Page: A thin page built only to capture a query and funnel users elsewhere. A guideline violation.
Duplicate Content: Substantially identical content on multiple URLs. Resolve with canonicals, redirects or consolidation.
Dwell Time: How long a searcher stays before returning to the results. Not a confirmed ranking factor, but a good quality proxy.

E

E-E-A-T: Experience, Expertise, Authoritativeness and Trust, the quality framework Google's raters use to judge content.
Editorial Link: A link a publisher chose to give because your page was worth citing. The type that holds value long term.
Entity: A person, place, organisation or concept search engines understand as a distinct thing, not just a keyword string.
Exact Match Anchor: Anchor text identical to the target keyword. Effective in moderation, a footprint when overused.

F

Faceted Navigation: Filter and sort parameters on category pages. Left uncontrolled they generate thousands of duplicate URLs.
Featured Snippet: A short answer lifted to the top of the results. Won by answering the question directly in clear, structured copy.
First Contentful Paint: How long until the browser renders the first piece of content.
Footprint: A repeated pattern across links or sites that makes a scheme detectable, same templates, hosts or anchor mixes.

G

Google Business Profile: The listing that powers your presence in maps and local packs. Central to local SEO.
Google Search Console: Google's free reporting on impressions, clicks, indexing and technical issues for your verified site.
Guest Post: An article you write for another publication. Legitimate when the audience is real and the content earns its place.
Guidelines: Google's published rules on spam and quality. The line between aggressive and reckless SEO.

H

H1: The main heading of a page. Use one, and make it match search intent.
Heading Hierarchy: Logical use of H1 to H6 so both users and crawlers can follow the structure of a page.
Hreflang: Markup that tells search engines which language and region version of a page to serve.
HTTP Status Code: The server's numeric response, 200 fine, 301 moved permanently, 404 missing, 500 server error.
HTTPS: Encrypted delivery. A lightweight ranking signal and a baseline trust requirement.

I

Impression: One appearance of your page in a set of search results.
Index: The searchable database of pages a search engine has crawled and judged worth storing.
Index Bloat: Large numbers of thin, duplicate or parameter URLs in the index, diluting crawl attention.
Indexation: Whether a page is stored in the index and therefore eligible to rank at all.
Information Architecture: How pages are grouped and linked so importance and relationships are obvious.
Interaction to Next Paint: The Core Web Vital measuring responsiveness to user input; it replaced First Input Delay.
Internal Link: A link between pages on your own site. The cheapest, most controllable ranking lever you have.

J

JavaScript SEO: Making sure content rendered by JavaScript is still crawlable, indexable and fast.
JSON-LD: The recommended format for structured data, added as a script block rather than inline attributes.

K

Keyword: The word or phrase a person types or speaks into a search engine.
Keyword Cannibalisation: See Cannibalisation, multiple pages fighting over one query.
Keyword Density: How often a term appears relative to total words. A diagnostic for over-optimisation, not a target to hit.
Keyword Difficulty: A tool estimate of how hard it will be to rank for a term, usually based on the links of current top pages.
Keyword Mapping: Assigning one primary query to one page so effort and internal links do not compete.
Keyword Stuffing: Repeating a term unnaturally to manipulate rankings. Actively harmful.
Knowledge Panel: The entity summary box beside results, built from what search engines know about a brand or person.

L

Landing Page: The page a visitor arrives on, usually built around one intent and one action.
Largest Contentful Paint: A Core Web Vital measuring when the biggest visible element finishes rendering. Aim under 2.5 seconds.
Lazy Loading: Deferring off-screen images and media until needed. Speeds up first load when implemented crawl-safely.
Link Bait: An asset created specifically to earn links, original data, a free tool, a strong opinion piece.
Link Building: The practice of earning links from other sites to increase authority and rankings.
Link Equity: The ranking value passed through a link, once known as PageRank or link juice.
Link Exchange: Two sites agreeing to link to each other. At scale it becomes a detectable scheme.
Link Farm: A network of sites created purely to link out. Worthless at best, penalty bait at worst.
Link Gap: Domains linking to several competitors but not to you, the highest-probability outreach list you can build.
Link Insertion: Adding a link into an existing published article. Also called a niche edit or curated link.
Link Profile: The complete picture of your backlinks: sources, anchors, topics and growth over time.
Link Reclamation: Recovering value from broken, redirected or unlinked mentions of your brand.
Link Velocity: How quickly new links appear. Steady growth reads as natural; sharp spikes do not.
Local Pack: The map plus three business listings shown for local intent queries.
Log File Analysis: Reading server logs to see exactly what crawlers requested, how often and with what response.
Long-Tail Keyword: A longer, more specific query with lower volume and usually much clearer intent.

M

Meta Description: The summary snippet in the HTML head. It does not rank pages but strongly influences click-through.
Meta Robots Tag: Page-level instructions such as noindex or nofollow given to crawlers.
Mobile-First Indexing: Google indexes the mobile version of your site. Content hidden on mobile effectively does not exist.

N

Navigational Query: A search for a specific brand or site, such as a company name plus login.
Niche Edit: A link added to an existing, already-indexed article on a relevant site.
Nofollow: A rel attribute telling search engines not to pass endorsement through the link.
Noindex: A directive keeping a page out of the search index while still allowing users to visit it.

O

Off-Page SEO: Everything influencing rankings from outside your site: links, mentions, reviews, brand strength.
On-Page SEO: Optimising the content and HTML of a page, titles, headings, copy, internal links, markup.
Open Graph: Meta tags controlling how a URL previews when shared on social platforms.
Organic Traffic: Visits from unpaid search results.
Orphan Page: A page no internal link points to, so crawlers and users struggle to find it.
Outbound Link: A link from your page to another site. Citing good sources helps credibility.
Outreach: Contacting site owners, editors and journalists to earn coverage, links or partnerships.

P

Page Speed: How quickly a page loads and becomes usable. Affects both rankings and conversion.
PageRank: Google's original link-based scoring algorithm. No longer public, still conceptually alive.
Pagination: Splitting a long list across numbered pages. Keep the sequence crawlable and self-canonical.
Parasite SEO: Ranking content on someone else's high-authority domain. Effective, borrowed and unstable.
Penalty: A manual action or algorithmic suppression applied for guideline violations.
People Also Ask: The expandable related-question block in the results, a strong source of subheading ideas.
Pillar Page: The comprehensive central page of a topic cluster, supported by linked detail articles.
Private Blog Network: Sites owned or controlled solely to build links. A textbook black-hat tactic.
Programmatic SEO: Generating many templated pages from structured data. Works only when each page is genuinely useful.

R

Rank Tracking: Monitoring your positions for target queries across locations and devices.
Reciprocal Link: Mutual links between two sites. Fine occasionally, a pattern when systematic.
Redirect: Sending a request for one URL to another.
Redirect Chain: Two or more redirects between the requested URL and the final page. Collapse them to one hop.
Redirect Loop: Redirects pointing back at each other so the page never resolves.
Referring Domain: One unique website linking to you, however many individual links it sends.
Rel Canonical: See Canonical Tag.
Rel Sponsored: The rel value marking paid or sponsored links, required by Google's guidelines.
Rel UGC: The rel value marking user-generated links such as comments and forum posts.
Render Blocking: CSS or JavaScript that delays the browser from painting visible content.
Rich Result: A search result enhanced by structured data, reviews, FAQs, recipes, products.
Robots.txt: A root file telling crawlers which paths they may request. It controls crawling, not indexing.

S

Schema Markup: Standardised vocabulary describing your content to machines, usually implemented as JSON-LD.
Search Intent: What the searcher actually wants: to learn, compare, navigate or buy.
Search Volume: The estimated number of monthly searches for a query.
SERP: Search engine results page, everything shown for a query, ads and features included.
SERP Feature: Any non-standard result block: AI overviews, snippets, video carousels, map packs.
Server Log: The raw record of every request your server handled, crawlers included.
Server-Side Rendering: Producing full HTML on the server so content is present without executing JavaScript.
Session: One continuous visit by a user, ending after inactivity or a defined timeout.
Sitemap: An XML list of the URLs you want crawled and indexed, referenced from robots.txt.
Sitewide Link: A link repeated on every page, usually in a header, footer or sidebar. Counted roughly once.
Skyscraper Technique: Finding a heavily linked page, publishing something clearly better, then pitching it to those linkers.
Soft 404: A page returning 200 but showing no real content, so search engines treat it as missing.
Spam Score: A third-party estimate of how risky a domain looks. Screening input, never a verdict on its own.
Structured Data: Machine-readable markup describing your page, which can unlock rich results.
Subdomain: A separate hostname such as blog.example.com. Treated as related but partly distinct.
Subfolder: A path such as example.com/blog. Usually the better choice for consolidating authority.

T

Tail Query: A low-volume, highly specific search that often converts far better than a head term.
Technical SEO: Work on crawling, indexing, rendering, speed and site structure rather than copy.
Thin Content: Pages with little original value, whether auto-generated, scraped or simply padded out.
Title Tag: The clickable headline in search results. Front-load the primary term and stay under about 60 characters.
Topical Authority: Demonstrated depth and credibility across one subject area rather than scattered coverage.
Topical Relevance: How closely a linking site's subject matter matches yours. Often worth more than a higher authority score.
Toxic Backlink: A link from a spammy or manipulative source. Usually best ignored rather than disavowed.
Traffic Value: What your organic traffic would cost to buy through ads. A useful way to express SEO ROI.
Trust Flow: Majestic's estimate of link quality based on proximity to trusted seed sites.

U

Unlinked Mention: Your brand named without a link. The easiest outreach win available.
URL Slug: The readable part of a URL after the domain. Keep it short, lowercase and descriptive.
User Experience: How easily and pleasantly a visitor completes what they came to do.
User-Generated Content: Reviews, comments and forum posts contributed by your audience.

V

Vertical Search: Search restricted to one content type such as images, video, news or shopping.
Viewport: The visible area of a page on a given device; the meta viewport tag makes layouts responsive.

W

Web Vitals: The broader set of Google performance metrics, of which Core Web Vitals are the headline three.
White Hat SEO: Tactics that comply with search engine guidelines and hold their value over time.
White-Label SEO: Services delivered under an agency partner's brand rather than the provider's.

X

XML Sitemap: See Sitemap.

Z

Zero-Click Search: A search answered directly on the results page, so no site receives a visit.

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