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 refers to all practices aimed at optimizing content to appear in direct answers from search engines and AI assistants. It is a natural extension of SEO, focused on systems that synthesize a response rather than returning a list of links.

AI Overview

AI Overviews are Google's AI-generated summaries that appear at the top of SERPs for certain queries. Powered by Gemini, they synthesize a response from several identified web sources. Being cited as a source in an AI Overview is now the priority GEO objective on Google.

AI citation rate

The AI citation rate measures how frequently a brand, product, or piece of content is mentioned in LLM-generated responses across a set of tested queries. It is the baseline GEO monitoring metric and the starting point for any AI visibility analysis.

AI hallucination

AI hallucination refers to the phenomenon by which an LLM generates false, invented, or unverifiable information while presenting it with apparent confidence. It is a direct consequence of model architecture: models predict probable tokens without having access to factual truth.

AI share of voice

AI share of voice measures the proportion of LLM-generated responses in which a brand is cited, relative to the total citations within its sector. It is the central GEO monitoring metric and the AI equivalent of classic SEO share of voice.

B

Backlink

A backlink is a hyperlink from an external website pointing to your site. It is one of the main authority signals considered by Google: the more links a site receives from reliable sources, the more it is treated as a reference.

Brand hallucination

Brand hallucination is a specific form of AI hallucination in which a large language model generates inaccurate, fabricated, or misleading information about a company, its products, or its positioning. It is one of the primary brand risks introduced by the rise of generative AI in search.

C

Crawl

Crawling is the process by which search engine robots traverse a site's pages by following links, to discover and analyze content. It is the step that precedes any indexing: an uncrawled page is an invisible page.

D

Domain Authority

Domain Authority (DA) is a metric developed by Moz that estimates a website’s ranking potential on a scale from 0 to 100. Along with Domain Rating (Ahrefs) and similar scores, it is widely used as a proxy for a site’s overall link profile strength and organic visibility potential.

E

E-E-A-T

E-E-A-T is the evaluation framework used by Google's Quality Raters to assess the quality of content and the credibility of its source. It applies with particular rigor to YMYL topics, and indirectly influences the likelihood of content being cited by LLMs.

F

Featured Snippet

A featured snippet is a highlighted box displayed in position zero in Google's results, which directly pulls a content excerpt from a web page to answer a query. It is one of the most visible positions in the SERPs.

G

GEO (Generative Engine Optimization)

GEO refers to all practices aimed at optimizing a brand's visibility in responses generated by LLMs such as ChatGPT, Claude, or Perplexity. The goal is not only to drive direct traffic, but to be cited as a reliable reference in AI-generated answers.

H

I

Indexing

Indexing is the process by which a search engine decides to add a page to its database after crawling it. It is the prerequisite for any organic visibility: an unindexed page is invisible in SERPs, regardless of content quality.

Internal linking

Internal linking refers to the set of hyperlinks connecting pages within the same website. It is a direct SEO lever, entirely controlled in-house: it distributes authority across pages, guides Google's crawl, and creates thematic coherence that both search engines and LLMs can exploit.

J

K

Knowledge Panel

The Knowledge Panel is a structured information card displayed by Google to the right of SERPs for recognized entities (brands, people, places, organizations). Fed by Google's Knowledge Graph, it is a strong credibility signal for users and LLMs alike.

L

LLM (Large Language Model)

An LLM (Large Language Model) is an artificial intelligence model trained on large amounts of text to generate, understand, and synthesize natural language. ChatGPT, Claude, Gemini, and Mistral are LLMs. They form the foundation of AI answer engines.

Link building

Link building refers to all actions aimed at obtaining hyperlinks (backlinks) from external websites pointing to your own site. It is the pillar of off-page SEO: the quality of a site's link profile is one of the most decisive authority signals for Google.

Link juice

Link juice (or link equity) refers to the SEO value transmitted from one page to another via a hyperlink. It is the founding mechanism of PageRank: every link redistributes a fraction of the authority accumulated by the source page to its destinations.

M

Messy Middle

The messy middle refers to the non-linear, exploration-heavy phase of the customer decision journey between an initial trigger and a purchase decision. In this zone consumers loop through exploration and evaluation, and brand visibility in AI responses now plays a decisive role.

N

Noindex

Noindex is a directive that instructs search engine robots not to include a specific page in their index. Applied via a meta robots tag or HTTP header, it is the primary technical lever for controlling which pages appear in search results.

O

On-page optimization

On-page optimization refers to all SEO techniques applied directly on a site's pages: title tag, H1/H2 structure, content, internal linking, structured data, images. It is the most directly controllable lever in SEO.

Organic Traffic

Organic traffic refers to the visits a website receives from unpaid search engine results. It is the primary success metric of SEO: every click generated through a natural Google ranking is organic traffic, tracked via Google Search Console and Google Analytics.

P

People Also Ask

People Also Ask (PAA) are blocks of related questions displayed by Google in SERPs. Each question unfolds a short answer extracted from a web page. Appearing in these blocks provides additional visibility and constitutes a relevance signal directly exploitable for GEO.

Q

Query fan-out

Query fan-out is the mechanism by which an LLM breaks down a complex question into multiple complementary sub-queries to interrogate different sources before synthesizing a final response. It is a core mechanism of RAG systems like Perplexity.

R

RAG (Retrieval-Augmented Generation)

RAG is a technique that extends an LLM by allowing it to retrieve information in real time from external sources before generating its response. Perplexity and Bing Copilot operate on this principle. It's what enables an LLM to cite up-to-date sources.

S

SEO (Search Engine Optimization)

SEO refers to all techniques aimed at improving a website's ranking in the organic results of search engines. It rests on three pillars: technical optimization, content quality, and domain authority.

SERP

A SERP (Search Engine Results Page) is the page displayed by a search engine in response to a query. It no longer contains only blue links: AI Overviews, featured snippets, knowledge panels, local results, images, videos, PAA, and ads coexist and redefine the visibility zones worth targeting.

Search intent

Search intent refers to the actual goal behind a query entered in a search engine. Google evaluates this intent to decide what type of page and content deserves to rank. Ignoring intent means producing content that will never rank.

Structured data

Structured data is a semantic markup added to a page's HTML code to explicitly tell search engines what type of content is being presented. It uses the Schema.org vocabulary and is implemented as JSON-LD. It enables rich results in SERPs and facilitates citation by LLMs.

T

U

URL structure (SEO)

URL structure refers to how a web page's address is constructed. An SEO-friendly URL is short, descriptive, human-readable, and contains the main keyword. It helps search engines understand the page and improves CTR in SERPs.

V

Voice Search

Voice search refers to queries made out loud via assistants like Siri, Google Assistant, or Alexa. These queries are formulated in natural language, longer and more conversational than text searches, and share the same optimization levers as AEO and GEO.

W

Webmaster Tools

Webmaster Tools refer to the tools provided by search engines to monitor and optimize a site's presence in their results. Google Search Console and Bing Webmaster Tools are the two reference platforms.

X

XML Feed

An XML feed is a structured file that allows external systems to automatically read and import a website's content. In SEO, XML feeds are used for sitemaps, e-commerce product feeds, and content syndication.

Y

YMYL (Your Money or Your Life)

YMYL (Your Money or Your Life) refers to content categories that can have a direct impact on people's health, financial security, or wellbeing. Google applies particularly strict E-E-A-T evaluation criteria to these pages because incorrect information can cause real harm.

Z

Zero-click search

A zero-click search is a query for which the user obtains their answer directly in the SERP without clicking on any site. Featured snippets, AI Overviews, Knowledge Panels, direct answers, and calculations are the main generators. This phenomenon redefines the strategic value of certain SEO positions.