Glossary

GEO, AEO, and AI search terms, defined plainly.

The vocabulary around AI search moves fast. Here is what the key terms actually mean for a service business trying to get cited.

Generative Engine Optimization

GEO

The practice of structuring content so that AI-generated answer engines select it as a source when responding to relevant queries. GEO optimizes for citation in AI answers rather than for keyword ranking in traditional search results.

The core difference between GEO and SEO is the optimization target. SEO targets a position in a ranked list. GEO targets inclusion in a synthesized answer. The user experience is different: in SEO, the user picks from a list. In GEO, the engine picks for them. The business that gets cited is the one that gets the traffic.

AI search adoption grew from 8% to 40% in one year. (DOJO AI, Jan 2026)

Answer Engine Optimization

AEO

Optimization of content to appear in direct answer formats, including Google's featured snippets, People Also Ask boxes, and AI-generated answer panels. AEO predates GEO and was originally focused on traditional search answer boxes.

In current usage, AEO and GEO often describe the same practices, with GEO specifically emphasizing AI engine citation and AEO sometimes used more broadly to include traditional search answer features. Both require answer-first content structure, schema markup, and specific, verifiable claims.

Share of Model

SoM

The percentage of AI-generated answers in a given topic category or query set that cite a specific brand or domain as a source. Share of Model is the AI-search equivalent of Share of Voice in traditional marketing.

A service business with 0% Share of Model for queries about their service category is invisible to AI engines for those queries. Increasing Share of Model is the primary measurable goal of a GEO strategy.

92% of brands currently have 0% Share of Model in ChatGPT. (Snezzi, 2026)

Citation score

A 0 to 100 signal measuring how well a piece of content is structured for AI citation. The score combines roughly a dozen inputs: answer-format clarity (is the answer in the first 80 words?), statistical density, outbound citation count, E-E-A-T signals, schema readiness, sentence structure, freshness, and topical authority within the domain's subject area.

A citation score is a pre-publication validation tool: it catches structural gaps before the content goes live, rather than after citation tracking shows the post is being skipped.

Above 75 is publish-ready. Below that, the score breakdown identifies the specific missing signals.

Voice profile / voice fingerprint

A set of measurable writing characteristics extracted from a content creator's samples: average sentence length, formality level, technical vocabulary density, paragraph length patterns, and explanation structure (does the writer put the conclusion first or build to it?). The fingerprint is used to constrain AI-generated content to match the creator's documented writing habits.

Voice fingerprints matter for AI citation because specificity is a citation signal, and voice-matched content tends to produce more specific claims. Generic content that sounds like no one in particular gets passed over. Content that sounds like a specific expert in a specific domain gets cited.

Eight writing samples is the practical minimum for reliable voice matching.

Brand-bound citation rate

The rate at which a specific brand or domain is cited when a user asks a query that includes that brand's name or a closely related term. A high brand-bound citation rate means that when users ask about your services or your competitors' services, AI engines include your content in their answers.

Brand-bound citation rate is a useful early metric because brand-name queries are specific and the competition is narrow. It is easier to achieve a citation when someone asks "who handles historic-home HVAC retrofits in Austin" than when they ask "best HVAC company near me."

Citation-worthy content

Content structured and substantiated in a way that AI engines are likely to select as a source. Citation-worthy content has: a direct answer in the first 80 words, at least one specific statistic with a named source, an author with verifiable credentials, FAQPage or HowTo schema, and specific rather than generic claims.

Princeton GEO research from 2023 found that citing sources and adding statistics improves AI citation visibility by 30 to 40%. Citation-worthy content implements those findings systematically.

E-E-A-T

Experience, Expertise, Authoritativeness, and Trustworthiness. Google's quality evaluation framework for content, applied by human quality raters and embedded in algorithmic signals. AI Overviews use the same underlying criteria when selecting sources.

For service businesses: Experience is documented track record (job counts, project outcomes). Expertise is credentials and certifications in machine-readable schema. Authoritativeness is consistent topical publishing and local market reputation. Trustworthiness is transparent policies, verifiable claims, and primary source citations.

Zero-click search

A search session that ends without the user clicking through to any external website. The search engine or AI assistant answered the question directly on the results page, removing the need to visit the source.

Zero-click search accelerated significantly with the introduction of AI Overviews. For service businesses that previously relied on organic traffic, zero-click search means the citation is the traffic event, not the click. Being cited as the source in the answer panel matters more than ranking in the list below it.

60% of searches now end without a click due to AI summaries. (Bain, Feb 2025) CTR drops from 15% to 8% when an AI Overview is present. (Pew Research Center, Jul 2025)

LLM SEO

A broad term for the practice of optimizing content to appear in and be cited by large language model-powered search and answer tools. Sometimes used interchangeably with GEO or AEO. LLM SEO emphasizes the model-specific nature of the optimization: different models have different citation behaviors and retrieval approaches.

The practical distinction from traditional SEO: traditional SEO optimizes for a ranking algorithm. LLM SEO optimizes for content that a language model can extract, understand, and attribute. Schema markup, answer-first structure, and source citations are more directly relevant to LLM SEO than keyword density or backlink count.

AI Overviews

Google's AI-generated answer summaries that appear at the top of search results pages for many queries. AI Overviews pull from and cite multiple web sources, synthesizing a direct answer rather than presenting a list of links. Introduced broadly in 2024, they represent Google's integration of generative AI into its core search product.

For service businesses, AI Overviews have two implications. First, clicks from positions 1 to 3 on Google decrease because the AI Overview answers the question before the user reaches the organic results. Second, being cited inside an AI Overview creates visibility at the top of the page, above all organic results, for queries where Google selects your content as a source.

CTR drops from 15% to 8% when an AI Overview is present for a query. (Pew Research Center, Jul 2025)