Glossary

SEO & GEO Glossary

The essential terms of traditional and AI search, explained with a practitioner's perspective. Each definition is written to be directly useful.

A

AEO (Answer Engine Optimization)

AEO turns your content into the direct answer for AI. When a user asks ChatGPT, Perplexity, or a voice assistant a question, AEO determines whether your content gets extracted and cited, or a competitor's does.

AI Overview

AI Overviews are Google's AI-generated summaries that appear at the top of search results. They synthesize an average of 5 to 6 different sources. If you're not among them, you're invisible on that query.

AI citation rate

AI citation rate is the percentage of prompts tested on one or more LLMs where your brand, product, or content is mentioned. It's GEO's fundamental KPI. It allows you to objectively measure your presence in generative responses, track evolution over time, and evaluate the impact of your AI visibility actions.

AI hallucination

An AI hallucination is a false statement generated by an LLM with the same confidence as a verifiable fact. The model isn't lying: it completes a pattern without direct access to truth. For brands, the risk is twofold: being cited with wrong information, or not being cited at all because the model has insufficient knowledge.

AI share of voice

AI share of voice is the share of generative responses (LLMs, AI Overviews) in which your brand is mentioned, relative to competitors. It's the GEO equivalent of SEO share of voice. It tells you not just whether you're cited, but what position you occupy in your sector's landscape as AI describes it.

B

Backlink

A backlink is a hyperlink from an external site pointing to one of your pages. It's one of the most stable ranking factors in Google's history. In 2026, quality far outweighs quantity, and editorial backlinks also play an indirect role in LLM visibility.

Brand hallucination

Brand hallucination is the specific case where an LLM generates incorrect information about a company, product, or person. It's not a rare bug: it's a systemic risk for any brand under-represented or poorly represented in models' training data.

C

Crawl

Crawling is the zero step of SEO: before indexing a page, Google must first explore it via its Googlebot robot. In 2026, other robots join the picture: GPTBot, PerplexityBot, ClaudeBot. Each has its own access rules. If your site isn't crawlable, it's invisible, on Google and in AI alike.

D

Domain Authority

Domain authority is not a Google metric. It's a third-party score calculated by SEO tools (Moz, Ahrefs, Semrush) to estimate the strength of a site's link profile. Useful for comparisons, useless for predictions. In 2026, what really matters is the authority perceived by LLMs, and that can't be reduced to a number.

E

E-E-A-T

E-E-A-T is the framework Google uses to evaluate whether content deserves to rank well. Experience, Expertise, Authoritativeness, Trustworthiness: four dimensions that determine your credibility in the eyes of algorithms and generative AI.

F

Featured Snippet

A featured snippet is the box displayed at the top of Google results, before standard organic listings, known as position zero. But in 2026, its value goes beyond the click: content that earns a featured snippet is also far more likely to be cited in AI Overviews and by LLMs. Optimizing for featured snippets means optimizing for all AI extraction.

G

GEO (Generative Engine Optimization)

GEO (Generative Engine Optimization) is the practice of optimizing a brand's presence and visibility in AI-generated responses from platforms like ChatGPT, Perplexity, Google AI Overviews, and Claude. Unlike traditional SEO which targets rankings in a list of links, GEO targets direct citation within a synthesized answer.

H

I

Indexing

Indexing is the process by which Google adds a crawled page to its searchable database. An indexed page is eligible for search results. A non-indexed page is invisible. But indexing isn't automatic: Google decides based on content quality, uniqueness, and usefulness.

Internal linking

Internal linking is the set of hyperlinks connecting pages within the same site. It's one of the most under-exploited SEO levers: well built, it redistributes authority toward strategic pages, facilitates crawling, and guides users toward high-value content. Badly built, it leaves orphan pages invisible.

J

K

Knowledge Panel

The Knowledge Panel is the informational box displayed to the right of Google results when searching for a known entity: brand, person, place. It comes from Google's Knowledge Graph. In 2026, the Knowledge Panel is also a credibility signal for LLMs: entities recognized by Google are better represented in generative responses.

L

LLM (Large Language Model)

An LLM is the engine behind ChatGPT, Perplexity, Claude, and Gemini. It's the AI model that understands your questions, synthesizes sources, and generates the responses in which your brand gets cited. Or doesn't.

Link building

Link building (or netlinking) is the strategy of acquiring inbound links from third-party sites. It's one of the three pillars of SEO, alongside content and technical. In 2026, backlinks remain a major trust signal for Google, and editorial links also play an indirect role in LLM citability.

Link juice

Link juice (or link equity) is the SEO value transmitted by a hyperlink from one page to another. It's a metaphor for PageRank: the more authority a page receives from authoritative sources, the more juice it has to redistribute. Optimizing link juice distribution in your architecture is one of the most under-exploited technical SEO levers.

M

Messy Middle

The messy middle is the concept developed by Google to describe the non-linear exploration and evaluation phase separating awareness of a need from the act of purchase. In 2026, generative AI has radically transformed this phase: users increasingly trust LLM-synthesized responses to compare and decide.

N

Noindex

The noindex directive is an instruction you give Google asking it not to include a page in its search results. It's not a defensive tool: it's a precision tool for protecting your site's overall quality and concentrating authority on pages that deserve to be seen.

O

On-page optimization

On-page optimization covers everything you do directly on a page to improve its ranking: title tag, meta description, heading structure, content, internal links, structured data, Core Web Vitals. It's the first lever to activate before any link building work, because poorly structured content won't rank even with backlinks.

Organic Traffic

Organic traffic is all the visitors arriving on your site via unpaid search engine results. It's the central SEO indicator. In 2026, it must be interpreted with nuance: a decline in overall organic traffic may mask a rise in brand visibility through AI citations.

P

People Also Ask

People Also Ask (PAA) are the associated question boxes Google displays in search results. They reveal the sub-questions linked to a query and constitute a mine of intent signals. In 2026, they're also one of the best proxies for mapping the sub-queries generated by LLMs' query fan-out.

Prompt tracking

Prompt tracking is the practice of regularly testing a defined set of prompts across multiple LLMs to measure whether a brand, product, or content is cited in responses. It's the starting point of any GEO strategy: you can't optimize what you don't measure.

Q

Query fan-out

Query fan-out is the mechanism by which an AI transforms your question into 8 to 15 parallel sub-queries before generating a response. If your content doesn't answer these implicit sub-queries, it will never be extracted, even if you rank #1 for the main query.

R

RAG (Retrieval-Augmented Generation)

RAG is the mechanism that lets AI search your content on the web in real time before generating a response. It's why ChatGPT or Perplexity can cite your site today, even if it wasn't in their training data.

S

SEO (Search Engine Optimization)

SEO (Search Engine Optimization) is the set of practices aimed at improving a site's visibility in organic search results. In 2026, SEO has expanded: it's no longer just about ranking in 10 blue links, but being present in AI Overviews, featured snippets, and LLM responses.

SERP

The SERP (Search Engine Results Page) is the page Google displays in response to a query. In 2026, it has nothing to do with the old "10 blue links": AI Overviews, featured snippets, People Also Ask, and knowledge panels all coexist. Analyzing a SERP before producing content means understanding what Google considers the right answer. And therefore what you need to be.

Search intent

Search intent is the real goal a user pursues when typing a query. Google has made it a central ranking criterion: it doesn't reward the most keyword-optimized pages, but those that best answer what the user is truly looking for. Misaligning intent means working for nothing.

Structured data

Structured data is code added to your pages (typically in JSON-LD) that describes their content in a machine-readable language. In 2026, it's both an SEO lever (rich snippets, AI Overviews) and a GEO lever: it acts as a reading guide for LLMs, which extract and cite tagged pages more easily and reliably. Most sites aren't doing enough.

T

U

URL structure (SEO)

URL structure is how you organize and formulate your web page addresses. A well-built URL is short, readable, descriptive, and contains the primary keyword. It's a minor SEO signal but a major user experience factor, and a structural error can be costly during migrations.

V

Voice Search

Voice search is the act of submitting a query to a search engine or AI assistant by speaking rather than typing. It has accelerated the rise of AEO and GEO content: voice responses are single responses, extracted from one source. Either you are the source, or you're absent.

W

Webmaster Tools

Webmaster Tools primarily refers to Google Search Console (GSC) and Bing Webmaster Tools: the official search engine interfaces for monitoring a site's SEO health, analyzing search performance, and detecting indexing issues. GSC is the most useful free SEO tool that exists.

X

XML Feed

An XML feed is an XML-formatted file that lists or describes content in a machine-readable way. In SEO, we distinguish the XML sitemap (list of pages to index) from the RSS/Atom feed (new content stream). In 2026, sitemaps are also read by AI robots to discover your content.

Y

YMYL (Your Money or Your Life)

YMYL (Your Money or Your Life) designates content categories where incorrect information can have serious consequences on a user's health, safety, or finances. Google applies far stricter E-E-A-T criteria to this content. In 2026, LLMs apply a similar logic to avoid hallucinations on sensitive topics.

Z

Zero-click search

A zero-click search is a Google query that ends without any site being visited: the user gets their answer directly in the SERP. In 2026, over 60% of Google searches are zero-click. This isn't the death of SEO, it's the obligation to be present in the SERP itself.