Glossary of Digital Marketing, SEO, GEO and analytics
Short, citable definitions. New to SEO or GEO? Start here.
AARRR
AARRR is a five-stage growth model - Acquisition, Activation, Retention, Revenue and Referral - also known as the pirate funnel. It helps diagnose where the funnel breaks by measuring each stage separately. It applies to any business with a customer journey, not just startups.
See more →Ad Rank
Ad Rank is the value Google uses to decide whether your ad shows and in which position. It comes mainly from your bid multiplied by quality (the Quality Score), plus context and the expected impact of extensions. This is why a more relevant ad can beat a competitor who bids more: quality buys position without raising the bid.
See more →AEO
Answer Engine Optimization is optimizing for direct answers: featured snippets, People Also Ask and AI Overviews. It focuses on answering the question in an extractable way at the very start of the content. It's a cousin of GEO but narrower - AEO lives in Google's features, GEO extends to every AI engine.
See more →Agentic commerce
Agentic commerce is a purchase made by an AI agent on the user's behalf: the agent compares, decides, and increasingly completes the purchase. For a brand, being found by a person is no longer enough; you have to be chosen by a model. And that is decided by the quality and structure of your product data, not by your media budget. ChatGPT Shopping is the first version of this at scale.
See more →AI crawler (GPTBot, ClaudeBot, PerplexityBot)
An AI crawler is the bot AI providers use to crawl the web and feed their models and answers: GPTBot (OpenAI), ClaudeBot (Anthropic), PerplexityBot, Google-Extended, and others. Unlike Googlebot, most do not run JavaScript, so content that depends on rendering is invisible to them. Allowing or blocking them in robots.txt is a strategic GEO decision, not a box to tick by reflex.
See more →AI Overviews
AI Overviews are AI-generated answers at the top of Google results, for informational or complex queries. They summarize several sources and cite them, often without the user clicking. They already reach around 2.5 billion users a month and are a major driver of the rise in zero-click searches.
See more →Backlink
A backlink is a link from another site to yours. It's a signal of authority when it comes from relevant, credible sources - and noise (or risk) when it comes from low-quality ones. It remains one of the strongest SEO factors, and credible mentions also feed the trust AI uses to cite you.
See more →Canonical
A canonical tag tells the engine which is the preferred version of a page, consolidating signals and avoiding duplicate content. You use it when the same content lives on several URLs (parameters, variants). A misconfigured canonical can drop from indexing pages that should rank.
See more →CDN
A CDN (Content Delivery Network) is a network of distributed servers that delivers a site's content from the node closest to each user, to cut latency. It is the first point a request passes through, and in technical SEO a critical one: WAF rules, rate limiting or a bot challenge can block Googlebot and AI crawlers with nobody in marketing noticing. Auditing the CDN is part of auditing access.
See more →CMS
A CMS (Content Management System) is the system that manages a site's content creation, editing and publishing, such as WordPress, Drupal or a headless setup. It matters in technical SEO because it decides what goes into the HTML, how URLs, canonicals and sitemaps are generated, and how much control you have over titles, redirects and structured data. A badly configured CMS creates technical problems at scale; a well configured one prevents them at the source.
See more →Consent Mode
Consent Mode is Google's mechanism that adjusts tag behavior to the user's consent. It's required to measure EEA users in line with the GDPR. In v2, visits without consent fire cookielessly and GA4 models the missing conversions from consented data.
See more →Core Web Vitals
Core Web Vitals are Google's metrics measuring page experience: LCP (loading speed), INP (interaction responsiveness) and CLS (visual stability). They're one experience signal among many - they count, but don't beat relevance and quality. Measured in the lab (PageSpeed) and in the field (Search Console).
See more →Crawl
Crawl is the process by which engines follow links across a site to discover and revisit pages. If a page isn't crawled, it can't be indexed or appear in results. Managing crawl budget - not wasting it on low-value URLs - is a core part of technical SEO.
See more →CTR
CTR (Click-Through Rate) is the percentage of impressions that result in a click. It's a key metric in organic search, ads and video thumbnails - it measures how attractive your result is. With the rise of zero-click answers, organic CTR has fallen, which is exactly why GEO matters.
See more →DOM
The DOM (Document Object Model) is the tree of elements the browser builds from a page's HTML and JavaScript. Google indexes the final, rendered DOM. When content only appears after JavaScript runs, the initial DOM is empty, and AI crawlers, which do not execute JavaScript, see a different page from the user's. Comparing raw HTML with the rendered DOM is basic technical-SEO diagnosis.
See more →E-E-A-T
E-E-A-T stands for Experience, Expertise, Authoritativeness and Trust - the family of quality signals Google values, especially in sensitive topics (health, finance). It's not a single measurable score: it means showing who writes, with what first-hand experience and what sources. It's central to being cited by AI.
See more →Embedding (vectors)
An embedding is the representation of a text as a vector of numbers that captures its meaning. Texts with close meaning sit close together in that vector space, which lets you, at scale, cluster content, detect cannibalization, and suggest internal links by meaning rather than exact-match keywords. It is the mechanism behind much of modern SEO and how LLMs relate content.
See more →Entity
An entity is a real-world thing - brand, person, product - that engines and LLMs recognize and associate with attributes. It's the base of authority in GEO: before it cites you, the AI has to understand effortlessly who you are. You build it with consistent markup, verifiable sameAs and coherent presence across the web.
See more →Featured snippet
A featured snippet is the highlighted answer at the top of Google results, pulled directly from a page. It's the classic AEO target, won by answering the question directly and in a structured way (paragraph, list or table). It also feeds voice answers and AI Overviews.
See more →GA4
GA4 (Google Analytics 4) is Google's analytics platform, based on events rather than sessions like the old Universal Analytics. It measures behavior on the site and app to guide decisions. Configured well, with conversions tied to the business and Consent Mode, it's the measurement base for everything else.
See more →GDPR
GDPR (the EU General Data Protection Regulation) requires a legal basis and, for non-essential cookies, prior informed consent. In digital marketing it decides how you can measure and remarket: without valid consent there are no analytics cookies and no audiences, and Consent Mode models the gap. In Portugal, Law 41/2004 adds to it. Treating it as an obstacle is expensive; treating it as a baseline requirement avoids illegal measurement and data nobody trusts.
See more →GEO
Generative Engine Optimization is the practice of optimizing a brand's presence to be cited inside AI-generated answers - ChatGPT, Perplexity, Gemini, Copilot and Google's AI Overviews. The goal isn't to rank in a list of links: it's to be the source the model picks and cites. It rests on a clear entity, citable content, multi-engine reach and measurement.
See more →Google AI Mode
Google AI Mode is Google's conversational, AI-first search experience, separate from classic results, with follow-up questions and query fan-out into several sub-searches. It demands the same GEO strategy, only more thorough: topical depth, E-E-A-T and clean structure matter even more.
See more →Google Discover
Google Discover is a personalized Google feed, outside search, that distributes content by interest with no query. It's a high-volume but volatile channel, especially important for publishers. Eligibility comes from quality, large images, freshness, local relevance and E-E-A-T - not keywords.
See more →Google News
Google News is Google's news aggregator, with its own surfaces in search and the app. It requires news content, NewsArticle markup and compliance with specific editorial policies. It's a channel apart from Discover, though they share quality and freshness signals.
See more →Google Tag Manager (GTM)
Google Tag Manager is a tag manager that lets you implement and manage measurement (GA4, pixels, events, consent) without changing the site's code for every change. It centralizes and speeds up tagging work and makes the setup easier to maintain and audit.
See more →Grounding
Grounding is how an AI model anchors its answer in external sources fetched in real time, instead of answering only from what it learned in training. Gemini grounds on Google Search; ChatGPT with search goes to the Bing index. For a brand, it decides whether you are a cited source or left out: without presence in those layers, the model has nothing to anchor to.
See more →hreflang
hreflang is a technical signal that indicates the language or regional version of a page to serve each user, stopping Google from showing the wrong version per country. It's essential on multilingual sites and a frequent source of errors ("no return tag") when annotations aren't reciprocal.
See more →Indexing
Indexing is the inclusion of a page in the engine's index, making it eligible to appear in results. Crawling doesn't guarantee indexing: the engine decides whether the page has value and isn't duplicate. Indexing issues are among the most common causes of underperforming organic traffic.
See more →IndexNow
IndexNow is an open protocol that tells search engines within seconds when you publish, update, or remove a URL, instead of waiting for the next crawl. It is supported by Bing, Yandex, and others; Google tested it but does not adopt it. Because Bing feeds ChatGPT and Copilot, getting into the Bing index faster counts toward AI visibility. It is cheap to turn on and low-risk.
See more →Knowledge Graph
The Knowledge Graph is Google's knowledge base that links entities - people, brands, places - and their attributes and relationships. Being well-defined in it helps visibility in both search and AI, especially in Gemini, which leans on it. Signals like structured data, sameAs and Wikidata feed it.
See more →LLM
A Large Language Model is a large-scale model, trained on huge volumes of text, that generates and interprets natural language - it's what powers ChatGPT, Gemini or Claude. For GEO it helps to understand that an LLM knows both what it learned in training and what it fetches live when it searches.
See more →llms.txt
llms.txt is a text file at the site root that gives AI models context and guidance about the most important content, in a curated, citable format. It's an emerging proposal with no guarantee vendors use it, but it's low-cost and useful as a discipline of curating your best pages.
See more →North Star Metric
The North Star Metric is the single metric that best captures the value delivered to the customer and that, as it grows, pulls the business sustainably. It aligns teams around one definition of value and helps prioritize growth experiments. It differs from a KPI: it's the top that supporting KPIs ladder up to.
See more →OpenAI Ads (ChatGPT Ads)
OpenAI Ads (or ChatGPT Ads) is OpenAI's advertising platform that shows sponsored ads below ChatGPT's answers, always labeled and without influencing the answer. You buy on a CPC or CPM basis in Ads Manager; in Europe, history-based personalisation is off by default.
See more →People Also Ask (PAA)
People Also Ask is the box of related questions Google shows in results. Answering them directly in your content captures traffic, earns snippets and feeds AI answers. It's also an excellent source of ideas about what your audience wants to know.
See more →Performance Max (PMax)
Performance Max is the automated Google Ads campaign that serves ads across the entire Google network (Search, Display, YouTube, Discover, Gmail, Maps) from a single goal and your creative assets. It scales and simplifies, but gives little visibility into what works and depends on reliable conversion data. It suits accounts with conversions and volume that can watch it closely; it is not for starting from scratch or treating as a black box.
See more →PWA
A PWA (Progressive Web App) is a web application that runs like a native app, often with routing and rendering done on the client. In technical SEO it is a risk point: if pages assemble in the browser with JavaScript, the server ships an almost empty shell, and crawlers that do not run JavaScript see no content. To be indexable and citable by AI, a PWA needs to serve content already rendered (SSR or SSG).
See more →Quality Score
Quality Score is a Google Ads metric (0 to 10) evaluating the relevance of the ad, keyword and landing page. A higher score improves Ad Rank efficiency, letting you hold a position at a lower cost per click. It's where SEA and SEO meet: landing-page experience counts.
See more →Rendering
Rendering is the engine's interpretation of HTML and JavaScript to see the page as a user would. Rendering failures hide JavaScript-dependent content and can mean Google never sees what's actually on the page. It's critical on sites built with JavaScript frameworks.
See more →ROAS
ROAS (Return on Ad Spend) is the revenue generated per unit invested in advertising - a ROAS of 4 means 4 in revenue for every 1 spent. It's the central metric for judging paid-campaign efficiency, and it's only reliable with properly configured conversion tracking.
See more →robots.txt
robots.txt is a root file that guides crawlers on what they may or may not crawl. It's also where you allow (or not) AI crawlers like GPTBot and PerplexityBot - a strategic GEO decision. Note: blocking crawling isn't the same as preventing indexing.
See more →SEA
Search Engine Advertising is paid advertising on search engines, mainly Google Ads on the search network. It shows ads to people actively searching for what you offer, you pay per click, and it captures high-intent demand immediately and measurably. It complements SEO: one brings traffic now, the other builds and sustains.
See more →Search intent
Search intent is the goal behind a query - informational, navigational, commercial or transactional. Reading the right intent is what decides the type of content to create: a guide, a service page, a comparison. Optimizing for the right keyword with the wrong intent is wasted effort.
See more →SEM
Search Engine Marketing is the umbrella term covering SEO and SEA - a brand's total presence on search engines, organic and paid. You use it when thinking about search strategy as a whole, coordinating what you earn organically with what you buy.
See more →SEO
Search Engine Optimization is the set of practices that make a site eligible and competitive in organic search results. It works on three fronts: a technical base (crawl, indexing, speed), content aligned with search intent, and authority (links and trust signals). It's medium-term, but it compounds over time and lowers the cost of acquisition.
See more →SERP
A SERP (Search Engine Results Page) is the results page for a query. Today it's far more than ten blue links: it includes featured snippets, People Also Ask, knowledge panels and AI Overviews, all competing for attention. Understanding the SERP makeup of each query guides the right strategy.
See more →Sitemap
A sitemap is an XML file listing a site's URLs to help engines discover and prioritize them. It doesn't force indexing, but it speeds discovery, especially on large or new sites. It should contain only canonical, indexable URLs - noindex or duplicate pages don't belong there.
See more →Structured data
Structured data is markup (using the Schema.org vocabulary) that describes content for machines, enabling rich results and better understanding by engines and LLMs. It helps define entities and make content citable. Mark up what applies and is true - misleading markup can trigger a manual penalty.
See more →Zero-click search
A zero-click search ends without a click to any site, because the answer already shows on the SERP itself: a featured snippet, a knowledge panel, or an AI Overview. These are now most searches, and they change the metric of success: you stop measuring clicks alone and start measuring presence and citation inside the answer. It's the whole reason GEO exists.
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Frequently asked questions
What is this glossary for?
It gathers the essential terms of digital marketing, SEO, GEO and analytics in short, citable definitions. It helps anyone starting out and anyone aligning language across a team. See services →
How is it organized?
Terms are listed alphabetically, and each one links to the service or resource where the topic is covered in depth. Click the term or See more to go deeper. See services →
Can I cite these definitions?
Yes. They are short and written to be cited, including by AI systems. Each definition stands on its own; if you use one elsewhere, a source credit is welcome. Get in touch →