Citanta.

Terminology

One service, seven names.

The AI search optimization industry has no standard vocabulary. Here is what GEO, AEO, LLMO, AIO, AI SEO, GXO, and AISO each mean — and which one you actually need.

GEO
Generative Engine Optimization
Most used in 2026

Optimizing content to be cited by AI systems (ChatGPT, Perplexity, Gemini) when they generate responses. Formally defined by Princeton researchers in November 2023. This is the primary brand term.

Who uses it: Most agencies, Semrush, marketing publications, academic research.

AEO
Answer Engine Optimization
Older term, repurposed

Originally about featured snippets and voice search. Now repurposed to include AI-generated answers. Broader than GEO — covers featured snippets, voice assistants, and AI chat responses.

Who uses it: SEO agencies transitioning to AI, voice-search specialists, Google-focused marketers.

LLMO
Large Language Model Optimization
Technical circles

A technical subset of GEO focused on how LLMs retrieve and cite content through training data and RAG pipelines. Functionally similar to GEO with a more technical framing.

Who uses it: Technical marketers, AI engineers, developer-tool companies.

AIO
AI Optimization / AI Overviews
Two meanings

Two meanings: (1) an umbrella term covering GEO + AEO + LLMO, or (2) Google's 'AI Overviews' summaries at the top of results. Context determines which is meant.

Who uses it: Enterprise agencies (umbrella) and the Google/SEO community (Overviews).

AI SEO
AI Search Engine Optimization
Ambiguous

Two different meanings: (1) optimizing for AI search engines (same as GEO), or (2) using AI tools to do traditional SEO faster. Always ask which is meant.

Who uses it: Freelancers, marketplaces, agencies without clear positioning.

GXO
Generative Experience Optimization
Niche / emerging

A newer term focused on the full user experience within an AI-generated answer, not just being cited. Less common but appearing in 2026 trend publications.

Who uses it: A few forward-thinking agencies and trend publications.

AISO
AI Search Optimization
Rare / contested

Another synonym for GEO. Used by a handful of agencies but considered contested, with no clear distinct meaning.

Who uses it: A handful of agencies trying to own a unique term.

Frequently asked questions

Are GEO, AEO, and LLMO the same thing?

Largely yes. They all describe optimizing content to be cited by AI engines, with differences in emphasis: GEO is the dominant general term, AEO comes from the answer/snippet world, and LLMO is a more technical framing.

Which term should I use for my business?

Use GEO as your primary term — it has the widest recognition in 2026 — while including AEO, LLMO, and AI SEO in your content so you're found regardless of which name a prospect searches.

What does AIO mean?

AIO has two meanings: an umbrella term covering GEO, AEO, and LLMO; or Google's 'AI Overviews.' Context determines which is meant.

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