AEO, GEO, LLMO, SEO: the glossary of the new search acronyms

Search has changed more in two years than in the previous twenty. SEO still matters, but attention is shifting to a new family of acronyms — GEO, AEO, LLMO… — that describe how to be visible inside AI answers. This glossary defines them clearly and, above all, lists the KPIs specific to GEO with, for each, the strategy that works to improve it.

The main optimization families

They all aim at the same thing — being found — but on different terrain. The key distinction: SEO = rank in a list; GEO/AEO = get included in an answer.

• SEO — Search Engine Optimization. Optimization for classic engines (Google, Bing): ranking high in the list of links. Still useful, but no longer the only battleground.
• SEM / SEA — Search Engine Marketing / Advertising. Marketing on search engines, organic (SEO) and paid (Google Ads).
• AEO — Answer Engine Optimization. Optimization for "answer engines" that give a direct answer rather than a list. Goal: be the answer, not a link.
• GEO — Generative Engine Optimization. Optimization for generative engines (ChatGPT, Gemini, Perplexity, Copilot). Goal: be cited or recommended inside an AI-written answer. This is the heart of the matter.
• LLMO — Large Language Model Optimization. A variant focused on large models: making sure an LLM knows your brand and represents it correctly.
• GAIO — Generative AI Optimization. A common synonym of GEO.
• AIO — AI Optimization. Optimization for AI in general, or shorthand for Google's AI Overviews.

In practice, GEO, LLMO, GAIO and AEO overlap heavily: all aim to make you a source the AI cites.

The technology behind AI answers

Understanding these terms helps you understand how to get cited.

• LLM — Large Language Model. The model that generates the text (GPT, Gemini, Claude, Llama…), from its training and, sometimes, live search.
• RAG — Retrieval-Augmented Generation. The model first retrieves relevant documents, then writes its answer from them. This enables real-time citations.
• NLP — Natural Language Processing. The automatic processing of language.
• AI Overviews. The AI-generated summary at the top of Google results, with a few sources. Formerly SGE — Search Generative Experience.
• Knowledge Graph / Knowledge Panel. Google's knowledge base about entities; appearing there strengthens how AIs recognize you.
• llms.txt. A proposed standard file telling models which content to prioritize — the equivalent of robots.txt for LLMs.

The SEO basics to keep in mind

GEO builds on a few SEO fundamentals, without being limited to them: E-E-A-T (experience, expertise, authoritativeness, trustworthiness) feeds AI trust, and structured data (Schema.org) make your content easier to extract. The notions of SERP, featured snippet and zero-click are still worth knowing, but the stakes clearly shift toward being cited in generative answers.

The glossary of GEO-specific KPIs

Measuring GEO requires new indicators. For each, here is its definition and the strategy that works to improve it.

KPI	Abbr.	Definition	How to improve it
Citation Rate	CR	The share of AI answers, across tested queries, where your brand is cited or recommended.	Answer real customer questions clearly and factually, in extractable headings and Q&A.
AI Share of Voice	SoV	Your citation frequency versus competitors on the same queries.	Cover more queries than they do and multiply reliable sources that mention you.
Mention Rate	MR	How often your brand is named, whether or not linked as a source.	Build brand awareness: press, directories, reviews, partners.
Position in the answer	POS	Where you appear: first, middle, end.	Aim for the direct answer and topical authority (E-E-A-T).
Sentiment	SENT	The tone of the mention: positive, neutral, negative.	Cultivate positive reviews and content, fix negative sources.
Accuracy	ACC	How correct what the AI says about you is.	Publish consistent, up-to-date info everywhere (site, profiles, Wikidata).
Prompt Coverage	PC	The number of relevant queries for which you are cited.	Create dedicated content for each target intent / query.
Share of Citations	SoC	Among sources cited on a query, the share that goes to you.	Become the reference source: in-depth content, original data.
AI Referral Traffic	ART	Visits arriving from ChatGPT, Perplexity, etc.	Make people want to click: added value and a memorable brand.
Recommendation Rate	RR	The share of answers where you are actively recommended.	Stack quality proof (reviews, rankings, case studies) the AI can reuse.

Optimizing for GEO means making your content clear, factual and consistent everywhere: that is what makes an AI cite you.

Conclusion

AEO, GEO and LLMO aren't fads: they are the new ways of being found when your customers ask an AI. Keep this glossary handy, focus on the GEO KPIs that matter, and apply the strategies above. To see where you stand right now, start with a free audit of your visibility in AI answers with Sapian Metrics.