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SEO Library

The SEO Library

135 SEO and marketing concepts explained in plain English — what each one means, why it matters, how to apply it and the mistakes to avoid.

All topics AI Search 3 Analytics 10 Content 14 Fundamentals 30 Local SEO 4 Off-Page SEO 10 On-Page SEO 13 Technical SEO 51

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Technical SEO 301 Redirect A 301 redirect is a permanent redirect that sends users and search engines from one URL to another and signals that the… Technical SEO 404 Error A 404 error is the HTTP status a server returns when a requested page doesn't exist. Some 404s are normal; 404s on… Technical SEO 404 Error A 404 error is the HTTP status a server returns when a requested page doesn't exist. Some 404s are normal; 404s on…

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Fundamentals Above the Fold "Above the fold" is the part of a web page visible without scrolling. It shapes first impressions, conversions and loading priorities such… Fundamentals Above the Fold "Above the fold" is the part of a web page visible without scrolling. It shapes first impressions, conversions and loading priorities such… AI Search AI Overviews AI Overviews are AI-generated summaries that Google shows at the top of some search results, combining information from multiple web pages and… Fundamentals Algorithm Update An algorithm update is a change to how a search engine ranks results. Google makes changes constantly and announces larger "core" and… Fundamentals Algorithm Update An algorithm update is a change to how a search engine ranks results. Google makes changes constantly and announces larger "core" and… Technical SEO AMP (Accelerated Mobile Pages) AMP is an open-source framework for building fast mobile pages. It was once required for some Google features, but that is no… Technical SEO AMP (Accelerated Mobile Pages) AMP is an open-source framework for building fast mobile pages. It was once required for some Google features, but that is no… On-Page SEO Anchor Text Anchor text is the visible, clickable text of a hyperlink. Search engines use it as a clue to what the linked page… AI Search Answer Engine Optimization (AEO) Answer Engine Optimization (AEO) is the practice of structuring content so AI assistants, voice search and answer features like AI Overviews and…

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Off-Page SEO Backlinks Backlinks are links from other websites to yours. Search engines treat relevant, editorially earned backlinks as votes of confidence, making them one… Off-Page SEO Black Hat SEO Black hat SEO means tactics that try to manipulate search rankings in violation of search engine guidelines — such as cloaking, link… Analytics Bounce Rate Bounce rate is the share of sessions where a visitor didn't meaningfully engage. In GA4 it is the opposite of engagement rate;… Fundamentals Branded Keywords Branded keywords are search queries that include a brand, company or product name, such as "iftikhar seo library". Non-branded keywords describe a… On-Page SEO Breadcrumbs Breadcrumbs are a secondary navigation trail (Home › Category › Page) showing where a page sits in the site's hierarchy. They help… Technical SEO Broken Links Broken links point to pages that no longer exist or return errors. They frustrate users, waste crawl effort and lose link value,…

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Technical SEO Canonical Tag A canonical tag (rel="canonical") is an HTML element that tells search engines which URL is the preferred version of a page when… Local SEO Citation (Local SEO) In local SEO, a citation is any online mention of a business's name, address and phone number (NAP) — on directories, social… Analytics Click-Through Rate (CTR) Click-through rate (CTR) is the percentage of people who click a result after seeing it. In SEO, organic CTR equals clicks divided… Technical SEO Cloaking Cloaking is showing different content or URLs to search engines than to human visitors in order to manipulate rankings. It violates Google's… Content Content Pruning Content pruning is reviewing existing pages and improving, merging, redirecting or removing those that add little value, so the site's overall quality… Content Content Pruning Content pruning is reviewing existing pages and improving, merging, redirecting or removing those that add little value, so the site's overall quality… Analytics Conversion Rate Conversion rate is the percentage of visitors or sessions that complete a desired action — such as a purchase, form submission or… Technical SEO Core Web Vitals Core Web Vitals are three Google metrics that measure real-user page experience: Largest Contentful Paint (loading), Interaction to Next Paint (responsiveness) and… Technical SEO Crawl Budget Crawl budget is the number of URLs a search engine is willing and able to crawl on your site in a given… Technical SEO Crawlability Crawlability is how easily search engine bots can discover and access the pages on your website through links, sitemaps and accessible server… Technical SEO Cumulative Layout Shift (CLS) Cumulative Layout Shift (CLS) is a Core Web Vital that measures how much visible content unexpectedly moves while a page is in… Technical SEO Cumulative Layout Shift (CLS) Cumulative Layout Shift (CLS) is a Core Web Vital that measures how much visible content unexpectedly moves while a page is in…

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Off-Page SEO Disavow Tool Google's Disavow Tool lets site owners ask Google to ignore specific backlinks. It's meant only for sites with a manual action for… Off-Page SEO Disavow Tool Google's Disavow Tool lets site owners ask Google to ignore specific backlinks. It's meant only for sites with a manual action for… Off-Page SEO Domain Authority Domain Authority (DA) is a third-party score from Moz that estimates how likely a website is to rank, based mainly on its… Technical SEO Duplicate Content Duplicate content is identical or very similar content that appears at more than one URL, on the same site or across different… Technical SEO Duplicate Content Duplicate content is identical or very similar content that appears at more than one URL, on the same site or across different… Analytics Dwell Time Dwell time is the period between a user clicking a search result and returning to the results page. It's a popular SEO…

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Content E-E-A-T E-E-A-T stands for Experience, Expertise, Authoritativeness and Trust — the framework Google's quality raters use to assess content quality. Trust is the… Analytics Engagement Rate (GA4) In Google Analytics 4, engagement rate is the percentage of sessions that were engaged — lasting longer than 10 seconds, having a… Fundamentals Entity (Entity SEO) In search, an entity is a distinct, well-defined thing — a person, company, place, product or concept — that Google can recognise… Fundamentals Entity (Entity SEO) In search, an entity is a distinct, well-defined thing — a person, company, place, product or concept — that Google can recognise… Content Evergreen Content Evergreen content stays relevant and useful for a long time — like guides, tutorials and definitions — and can attract search traffic… On-Page SEO External Links (Outbound Links) External links, or outbound links, are links from your website to a different domain. Linking to reputable sources helps readers verify claims…

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Technical SEO Faceted Navigation Faceted navigation lets users filter listings by attributes like size, colour, brand or price. It's great for shoppers but can create huge… Fundamentals Featured Snippet A featured snippet is a highlighted excerpt from a web page that Google shows near the top of results to answer a… Fundamentals Featured Snippet A featured snippet is a highlighted excerpt from a web page that Google shows near the top of results to answer a… Technical SEO First Contentful Paint (FCP) First Contentful Paint measures when the browser first renders any text or image from the page. It's a supporting speed metric (not… Technical SEO First Contentful Paint (FCP) First Contentful Paint measures when the browser first renders any text or image from the page. It's a supporting speed metric (not… On-Page SEO Focus Keyword A focus keyword (or primary keyword) is the main search phrase a page is designed to rank for. It guides the title,…

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Analytics Google Analytics 4 (GA4) Google Analytics 4 is Google's analytics platform that measures website and app usage with an event-based model, tracking sessions, engagement and key… Local SEO Google Business Profile Google Business Profile (formerly Google My Business) is a free listing that controls how a business appears in Google Maps and local… Analytics Google Search Console Google Search Console is a free tool from Google that shows how your site performs in Google Search — queries, clicks, indexing… Technical SEO Googlebot Googlebot is Google's web crawler — the software that discovers and fetches web pages so they can be rendered and indexed. It… Off-Page SEO Guest Posting Guest posting means writing an article for another website, usually with a byline and a link back to your own site. Done…

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On-Page SEO Header Tags (H1–H6) Header tags (H1 to H6) are HTML headings that structure a page's content into a hierarchy. They help readers scan and help… Content Helpful Content Helpful content is content created primarily for people — to inform, solve problems or help them decide — rather than mainly to… Technical SEO Hreflang Hreflang is an HTML attribute that tells search engines which language and regional version of a page to show to users, so… Technical SEO HTTP Status Codes HTTP status codes are three-digit responses a server sends for every request, telling browsers and crawlers whether a page loaded (200), moved… Technical SEO HTTPS HTTPS is the secure version of HTTP: data between the browser and the website is encrypted using TLS. It's a lightweight Google…

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On-Page SEO Image Alt Text Alt text (alternative text) is a written description of an image in the HTML alt attribute. Screen readers read it aloud, browsers… Technical SEO Index Bloat Index bloat happens when search engines index many low-value URLs — tag archives, filters, internal search pages, thin or duplicate pages —… Fundamentals Indexing Indexing is the process in which a search engine analyses a crawled page and stores it in its database (the index) so… Technical SEO Interaction to Next Paint (INP) Interaction to Next Paint is a Core Web Vital measuring how quickly a page visually responds to user interactions like taps, clicks… On-Page SEO Internal Links Internal links are hyperlinks from one page to another page on the same website. They help users navigate, help search engines discover…

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Technical SEO JavaScript SEO JavaScript SEO is the practice of making sure search engines can crawl, render and index content that depends on JavaScript — common… Technical SEO JSON-LD JSON-LD (JavaScript Object Notation for Linked Data) is the format Google recommends for adding structured data to web pages. It sits in…

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Content Keyword Cannibalization Keyword cannibalization happens when several pages on the same site target the same keyword and intent, so they compete with each other… On-Page SEO Keyword Density Keyword density is the percentage of times a keyword appears compared with the total words on a page. It's an outdated metric… Fundamentals Keyword Difficulty Keyword difficulty (KD) is a score from SEO tools estimating how hard it is to rank in the top 10 for a… Fundamentals Knowledge Graph Google's Knowledge Graph is a huge database of entities — people, places, organisations, things — and the facts connecting them. It powers… Fundamentals Knowledge Graph Google's Knowledge Graph is a huge database of entities — people, places, organisations, things — and the facts connecting them. It powers…

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Technical SEO Largest Contentful Paint (LCP) Largest Contentful Paint (LCP) is a Core Web Vital that measures when the largest image or text block in the viewport finishes… Technical SEO Largest Contentful Paint (LCP) Largest Contentful Paint (LCP) is a Core Web Vital that measures when the largest image or text block in the viewport finishes… Off-Page SEO Link Equity (Link Juice) Link equity, informally "link juice", is the ranking value that a link passes from one page to another. It depends on the… Local SEO Local Pack (Map Pack) The local pack is the map with three business listings that Google shows for searches with local intent, such as "dentist near… Fundamentals Long-Tail Keywords Long-tail keywords are specific, usually longer search phrases with lower individual search volume but clearer intent, less competition and often higher conversion…

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Fundamentals Manual Action A manual action is a penalty applied by a human reviewer at Google when a site violates Google's spam policies. Affected pages… Fundamentals Manual Action A manual action is a penalty applied by a human reviewer at Google when a site violates Google's spam policies. Affected pages… On-Page SEO Meta Description A meta description is an HTML attribute that summarises a page's content. It isn't a ranking factor, but search engines often show… Technical SEO Meta Robots Tag The meta robots tag is an HTML element in the page head that tells search engines how to index the page and… Technical SEO Meta Robots Tag The meta robots tag is an HTML element in the page head that tells search engines how to index the page and… Technical SEO Mobile-First Indexing Mobile-first indexing means Google predominantly uses the mobile version of a page's content for indexing and ranking. Since 2023 it applies to…

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Local SEO NAP Consistency NAP consistency means your business Name, Address and Phone number are identical everywhere they appear online — your website, Google Business Profile,… Off-Page SEO Negative SEO Negative SEO is an attempt to harm a competitor's search rankings — for example by pointing spammy links at their site, scraping… Off-Page SEO Nofollow Link A nofollow link carries the rel="nofollow" attribute, telling search engines the site doesn't vouch for the linked page. Google treats nofollow, sponsored… Technical SEO Noindex Noindex is a directive — in a meta robots tag or X-Robots-Tag header — that tells search engines not to include a…

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Off-Page SEO Off-Page SEO Off-page SEO covers everything that happens outside your own website to build its authority and reputation — mainly backlinks, but also brand… On-Page SEO On-Page SEO On-page SEO is the practice of optimising individual pages — content, title tags, headings, URLs, images, internal links and structured data —… On-Page SEO Open Graph Tags Open Graph tags are meta tags (og:title, og:description, og:image and others) that control how a page looks when shared on Facebook, LinkedIn,… Analytics Organic Traffic Organic traffic is visits that come from unpaid search results — clicks from Google, Bing and other search engines that you didn't… Technical SEO Orphan Page An orphan page is a page on your website that no other page links to. Search engines and visitors struggle to find…

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Technical SEO Page Speed Page speed is how quickly a web page loads and becomes usable. Google measures real-user speed mainly through Core Web Vitals; faster… Fundamentals PageRank PageRank is Google's original algorithm, created by Larry Page and Sergey Brin, that measures a page's importance based on the quantity and… Technical SEO Pagination Pagination splits long lists of content — blog archives, product categories, forum threads — across numbered pages (page 1, 2, 3…). Done… Technical SEO Pagination Pagination splits long lists of content — blog archives, product categories, forum threads — across numbered pages (page 1, 2, 3…). Done… Fundamentals People Also Ask (PAA) People Also Ask is a Google search feature showing expandable related questions, each with a short answer pulled from a web page.… Content Pillar Page A pillar page is a comprehensive guide to a broad topic that links to detailed cluster articles on each subtopic — and…

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Content Quality Rater Guidelines Google's Search Quality Rater Guidelines are a public handbook used by thousands of human raters to evaluate search results. Ratings don't change… Fundamentals Query (Search Query) A search query is the exact word or phrase a person types or speaks into a search engine. A keyword is the… Fundamentals Query Deserves Freshness (QDF) Query Deserves Freshness describes how Google favours recent content for searches where up-to-date information matters — breaking news, trending topics, recurring events…

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Analytics Rank Tracking Rank tracking is monitoring where your pages appear in search results for chosen keywords over time, by location and device. It's useful… Technical SEO Redirect Chain A redirect chain happens when a URL redirects to another URL that redirects again before reaching the final page (A → B… Technical SEO Rich Results Rich results are enhanced search listings that show extra information — star ratings, prices, availability, breadcrumbs, event dates, recipe times or video… Technical SEO Robots.txt Robots.txt is a plain-text file at the root of a website that tells search engine crawlers which URLs they may or may…

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Fundamentals Search Intent Search intent is the goal behind a search query — what the person actually wants to find or do. Matching intent is… Fundamentals Search Volume Search volume is the estimated average number of times a keyword is searched per month in a given location. It indicates demand,… Fundamentals SERP (Search Engine Results Page) A SERP — search engine results page — is the page a search engine shows in response to a query, combining organic… Fundamentals SERP Features SERP features are any search result elements beyond the standard blue link — such as featured snippets, AI Overviews, People Also Ask,… Fundamentals Sitelinks Sitelinks are additional links to other pages of a website shown beneath the main result, usually for branded searches. Google generates them… Fundamentals Sitelinks Sitelinks are additional links to other pages of a website shown beneath the main result, usually for branded searches. Google generates them… Technical SEO Soft 404 A soft 404 is a page that tells users it doesn't exist (or has almost no content) but returns a 200 OK… Technical SEO Soft 404 A soft 404 is a page that tells users it doesn't exist (or has almost no content) but returns a 200 OK… Technical SEO Structured Data (Schema Markup) Structured data is standardised code — usually JSON-LD using the Schema.org vocabulary — that describes a page's content to search engines, such…

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Technical SEO Technical SEO Technical SEO is the work that makes a website easy for search engines to crawl, render, index and understand — covering site… Technical SEO Technical SEO Technical SEO is the work that makes a website easy for search engines to crawl, render, index and understand — covering site… Content Thin Content Thin content is content that provides little or no value to users — such as near-empty pages, auto-generated text, doorway pages or… Technical SEO Time to First Byte (TTFB) Time to First Byte (TTFB) measures how long it takes from a browser's request until the first byte of the response arrives.… Technical SEO Time to First Byte (TTFB) Time to First Byte (TTFB) measures how long it takes from a browser's request until the first byte of the response arrives.… On-Page SEO Title Tag A title tag is the HTML element that defines a page's title. Search engines often use it as the clickable headline in… Content Topical Authority Topical authority is the perceived depth and reliability of a website on a specific subject, built by covering that topic comprehensively with…

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On-Page SEO URL Structure URL structure is how a website's addresses are organised — the domain, folders and slugs that make up each page's URL. Clean,… Technical SEO User Agent A user agent is the identifying string a browser or bot sends with each request, such as Googlebot's "Mozilla/5.0 (Linux; Android…) Googlebot/2.1".… Fundamentals User Experience (UX) Signals UX signals is a broad term for how a page's user experience may influence search performance — page experience factors like Core… Analytics UTM Parameters UTM parameters are tags added to a URL — utm_source, utm_medium, utm_campaign and others — that tell analytics tools like GA4 where…

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Content Video SEO Video SEO is optimising videos so they appear in Google video results, video packs, key moments and YouTube search — through titles,… Fundamentals Voice Search Voice search is searching by speaking to a device — Google Assistant, Siri, Alexa or a phone's mic. Voice queries tend to…

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Technical SEO Website Architecture Website architecture is how a site's pages are organised and linked together — navigation, categories, hubs and internal links. A clear, shallow… Fundamentals White Hat SEO White hat SEO means improving search visibility with methods that follow search engine guidelines and focus on people — useful content, good… Content Word Count Word count is the number of words on a page. It isn't a ranking factor — Google has said so directly —…

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Technical SEO X-Robots-Tag The X-Robots-Tag is an HTTP response header that gives search engines indexing instructions — like noindex or nofollow — for any file… Technical SEO X-Robots-Tag The X-Robots-Tag is an HTTP response header that gives search engines indexing instructions — like noindex or nofollow — for any file… Technical SEO XML Sitemap An XML sitemap is a file that lists the URLs you want search engines to crawl and index, often with the date…

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Content YMYL (Your Money or Your Life) YMYL — "Your Money or Your Life" — describes topics that could significantly affect a person's health, finances, safety or society. Google… Content YMYL (Your Money or Your Life) YMYL — "Your Money or Your Life" — describes topics that could significantly affect a person's health, finances, safety or society. Google…

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AI Search Zero-Click Searches A zero-click search ends without the user clicking any result, because the answer appeared on the results page itself — in an… Fundamentals Zero-Volume Keywords Zero-volume keywords are search terms that keyword tools report as having no (or almost no) monthly searches. Many are real, specific queries…

How to use the SEO Library

The SEO Library is a living glossary of the concepts that matter in search engine optimisation and digital marketing. Every entry starts with a one-paragraph definition you can quote, then explains why the concept matters, how to apply it on a real website and the mistakes that most often hold sites back.

Use the A–Z bar to jump to a letter, filter by topic, or type into the filter box to find a term instantly. When an entry connects to a deeper guide on the blog, you’ll find a link to it inside the entry.

Who it’s for

Business owners who want to understand what their SEO agency is talking about, marketers adding search to their skill set, developers who need the “why” behind SEO requests, and anyone studying for an SEO role. If a term you need is missing, tell me and I’ll add it.