SEO, AEO & GEO Glossary

Search has fractured into classic blue links, answer engines, and generative AI. The vocabulary has fractured with it. This is the working glossary we use at ThatDevPro — the same terms that show up in our audits, build specs, and client calls. Every definition is meant to be precise and vendor-neutral: what the term actually means, not how any one platform markets it. Terms are grouped roughly by what they govern, but search is a system, so most of them touch each other.

If a definition here ever drifts from how a search engine or standards body describes it, treat their documentation as the source of truth. We update this page as the field moves.

Search, Answer & Generative Optimization

SEO (Search Engine Optimization): The practice of improving a site's content, structure, and authority so it ranks well in organic (unpaid) search results. It spans technical health, on-page relevance, and off-page signals like links and reputation.
AEO (Answer Engine Optimization): Optimizing content so it can be selected and surfaced as a direct answer by answer engines — voice assistants, featured snippets, and AI-driven response boxes — rather than only as a ranked link. It emphasizes clear, self-contained, well-structured answers to specific questions.
GEO (Generative Engine Optimization): Optimizing content to be cited, summarized, or quoted by generative AI systems that compose answers from multiple sources. The goal is to be one of the sources a model draws from and attributes, rather than to rank a single URL.
AI Overviews (AIO): Google's AI-generated summaries that appear above traditional results for some queries, synthesizing an answer from multiple web pages with links to cited sources. Formerly tested under the name Search Generative Experience.
AI Mode: A conversational, AI-first search experience in which a user's query is answered by a generative model that can ask follow-ups and reason across multiple sources, rather than returning a static list of links.
SGE (Search Generative Experience): Google's earlier experimental name for generative AI summaries in search. Much of what SGE introduced was later launched and rebranded as AI Overviews.
E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness): A framework from Google's Search Quality Rater Guidelines used to assess content quality, with trust as the central pillar. It is not a direct ranking score but describes the qualities Google's systems aim to reward.
YMYL (Your Money or Your Life): Topics that could significantly affect a person's health, finances, safety, or wellbeing. Google holds YMYL content to a higher quality and trust bar because inaccurate information can cause real harm.
SQRG (Search Quality Rater Guidelines): Google's published manual for the human raters who evaluate search result quality. It does not change rankings directly, but it reveals the standards — including E-E-A-T and YMYL — that Google's algorithms are built to approximate.
Helpful Content System: A Google ranking component (now folded into the core ranking system) designed to reward content created primarily for people and to demote content made mainly to manipulate search rankings. It evaluates sites holistically, not just page by page.
Information Gain: The amount of new, non-redundant information a page adds beyond what already-ranking pages cover on the same topic. Content with high information gain gives a search or answer engine a reason to include it rather than another near-duplicate.
Entity Salience: How central or prominent a particular entity (a person, place, product, or concept) is to a piece of content. Higher salience signals that the page is genuinely about that entity rather than merely mentioning it.
Topical Authority: The depth and breadth of a site's coverage of a subject area, which can make it more likely to rank across many related queries. It is built by thoroughly covering a topic and its subtopics, not by publishing one strong page in isolation.
Query Fan-Out: A technique used by AI search where a single user query is expanded into several related sub-queries that are searched in parallel, then synthesized into one answer. Pages that comprehensively address the surrounding sub-questions are more likely to be drawn in.
Citation (AI): A reference an answer engine or generative model attaches to a generated answer, pointing to the source it drew from. In GEO, earning AI citations — being named and linked inside the answer — is the primary visibility goal.

Entities, Knowledge & Structured Data

Knowledge Graph: A database of entities and the relationships between them, used by search engines to understand things rather than just strings of text. It powers knowledge panels and helps engines disambiguate who or what a query refers to.
Schema.org: A shared, collaboratively maintained vocabulary of types and properties for describing things on the web (organizations, articles, products, events, and more). Search engines use it to interpret structured data consistently across sites.
JSON-LD (JSON for Linked Data): A format for embedding structured data as a JSON block, typically in a script tag in the page head. It is the format Google recommends for most schema markup because it keeps the data separate from visible HTML.
Structured Data: Machine-readable markup, usually following Schema.org, that describes a page's content in an explicit, standardized way. It helps engines understand context and can make a page eligible for enhanced search features.
sameAs: A Schema.org property that links an entity to other authoritative URLs describing the same entity — for example, its official social profiles or Wikipedia page. It helps engines reconcile a site's identity with the broader Knowledge Graph.
@id Graph: A pattern in JSON-LD where each node is given a stable @id URI so that entities can be referenced and connected across the page or across pages. This turns separate schema blocks into one interlinked graph instead of isolated objects.
Rich Result: A search result enhanced with extra visual or interactive features — star ratings, FAQs, recipes, event details — drawn from a page's structured data. Eligibility depends on valid markup and the engine's discretion; it is never guaranteed.
Featured Snippet: A highlighted answer box at the top of some search results that quotes a passage from a ranking page to answer a query directly. It is selected algorithmically from existing results, not submitted by the site owner.
Speakable: A Schema.org property that marks the sections of a page best suited to be read aloud by voice assistants. It signals which concise passages can be spoken back as an answer.
FAQPage: A Schema.org type for marking up a list of questions and their answers on a page. It tells engines the content is a genuine question-and-answer set, which can support answer-style presentation.
Breadcrumb: A navigational trail showing a page's position within a site's hierarchy, often marked up with BreadcrumbList structured data. It aids both user orientation and an engine's understanding of site structure.

Technical SEO, Crawling & Indexing

Canonical: A signal (commonly a rel="canonical" link) that names the preferred version of a page when duplicate or very similar URLs exist. It consolidates ranking signals onto one URL and reduces duplicate-content confusion.
hreflang: An attribute that tells search engines which language and regional version of a page to serve to which audience. It helps the right localized URL appear for the right users and avoids same-language versions competing with each other.
Crawl Budget: The number of URLs a search engine will crawl on a site within a given timeframe, shaped by crawl capacity and crawl demand. It mainly matters for very large sites, where wasted crawling can leave important pages undiscovered.
Internal Linking: The practice of linking between pages within the same site. It distributes authority, helps engines discover and prioritize pages, and signals the relationships between topics.
Hub-and-Spoke: A content and linking model where a central "hub" page covers a broad topic and links out to focused "spoke" pages on its subtopics, which link back to the hub. It is a common way to build and signal topical authority.
Mobile-First Indexing: Google's practice of using the mobile version of a page as the primary basis for indexing and ranking. Content, structured data, and metadata missing from the mobile rendering may not be considered.
NAP (Name, Address, Phone): A business's core contact details, which should be consistent everywhere they appear online. Consistent NAP supports local search and helps engines confirm a business is a single, trustworthy entity.
Local Pack: The block of local business results — typically a map with a short list of nearby businesses — shown for queries with local intent. Inclusion depends on relevance, distance, and prominence rather than classic page ranking alone.

Performance, Rendering & Accessibility

Core Web Vitals: A set of Google metrics measuring real-world user experience — loading, interactivity, and visual stability. They are part of Google's page experience signals and currently consist of LCP, INP, and CLS.
LCP (Largest Contentful Paint): A Core Web Vital measuring how long it takes for the largest visible content element to render, as a proxy for perceived load speed. Google considers 2.5 seconds or less, measured at the field level, to be good.
INP (Interaction to Next Paint): A Core Web Vital measuring overall page responsiveness by assessing the latency of user interactions throughout a visit. It replaced First Input Delay as the responsiveness metric; 200 milliseconds or less is considered good.
CLS (Cumulative Layout Shift): A Core Web Vital measuring how much visible content unexpectedly shifts during loading, capturing visual stability. A score of 0.1 or less is considered good.
Render Budget: The practical limit on the time, processing, and resources available to render a page before performance or crawler patience runs out. Staying within it means a page becomes visible and interactive without expensive work blocking the main thread.
Hydration: The process by which JavaScript attaches interactivity (event handlers and state) to server-rendered HTML in the browser. Heavy hydration can delay responsiveness and hurt interactivity metrics if not managed carefully.
Prerendering: Generating a page's HTML ahead of the request — at build time or in advance — so the content is delivered fully formed. It improves load performance and ensures content is present for crawlers without relying on client-side rendering.
Dynamic Rendering: Serving a pre-rendered, static version of a page to crawlers while sending the normal client-rendered version to users. Once a common workaround for JavaScript-heavy sites, it is now generally treated as a transitional measure rather than a long-term solution.
Content-First Architecture: An approach to building pages so that meaningful content and markup are present in the initial HTML response, before client-side scripts run. It keeps content reliably available to users, crawlers, and AI systems regardless of how much JavaScript loads.
Section 508: A U.S. federal law requiring information and communication technology — including websites — procured or used by federal agencies to be accessible to people with disabilities. Its technical requirements are aligned with the WCAG standard.
WCAG (Web Content Accessibility Guidelines): An internationally recognized set of guidelines from the W3C for making web content accessible to people with disabilities, organized around the principles that content be perceivable, operable, understandable, and robust. It is the reference standard cited by most accessibility laws and policies.