Almost every acronym the industry has coined for AI search (GEO, LLMO, AISO, GAIO, "AI SEO") describes the same job: making your business easy for AI engines to understand, quote, and recommend. Underneath the branding there are only two crafts: being quotable enough for an engine to lift your answer, and being credible enough for an engine to cite your name. This is the whole glossary in one place, so you don't have to decode another LinkedIn thread.
Why are there so many names for one discipline?
Because naming a discipline is the cheapest way to look like you invented it. When AI answers started displacing result pages, every agency, tool vendor, and newsletter writer rushed to name the new work, all at once and without consulting one another. The result is a pile of acronyms that sound like rival fields but describe overlapping slices of the same practice. This happens every time search shifts. It has never happened this fast, or produced this many logos.
The four main terms
SEO: search engine optimization
The original craft: earning rank in traditional results through crawlable pages, relevant content, and links. SEO still matters, and AI engines lean on its plumbing more than the hype admits: a page that cannot be indexed cannot be retrieved, read, or quoted either. Every other acronym on this list runs through it.
AEO: answer engine optimization
AEO is the craft of being quotable: structuring content so an engine can lift a clean, direct answer from your page. It predates ChatGPT (featured snippets and voice assistants built the discipline), but AI answers raised the stakes considerably. The unit of AEO is the passage: one question, answered plainly in the first sentence or two, in words a machine can reuse without rewriting.
GEO: generative engine optimization
GEO is the craft of being cited and recommended by generative engines: ChatGPT, Perplexity, Gemini and the like. Where AEO works at the level of the page, GEO works at the level of the entity: your name, your reputation, and your consistency across every source an engine might consult before deciding you are safe to mention. Reviews, directory listings, press, and third-party mentions all feed it.
AIO: AI Overviews optimization
AIO is the Google-specific slice: earning a place in the AI Overviews that now sit on top of many searches. It is less a separate craft than AEO and GEO applied to one very important surface. Google grounds those answers in indexed pages and known entities, so the same work feeds it. AIO is closer to a scoreboard than a discipline of its own.
Watch for a second meaning. Some people use AIO for AI optimization, a broad label for getting content used by any AI system, which makes it a near-synonym for GEO. The two get mixed up because the work overlaps, so when someone hands you an "AIO report", check which one it measures: AI Overview appearances and citations for your searches, or your visibility across several assistants. Outside marketing, AIO usually just means "all-in-one".
Which acronyms are just synonyms for GEO?
- LLMO (large language model optimization): GEO with the engine named differently. The goal is the same: get the models to know you and name you.
- AISO (AI search optimization): usually a straight synonym for GEO; occasionally stretched into an umbrella term for the whole field. Either way, it adds nothing new.
- GAIO (generative AI optimization): GEO again, with a spare word. Popular in European marketing circles.
- AI SEO, LLM SEO, ChatGPT SEO: informal umbrella labels people reach for before they have committed to an acronym. Imprecise, but harmless.
A useful test: if someone sells you LLMO and GEO as separate line items, ask what differs in the deliverables. If the answer is "the invoice," you have learned something about the vendor too.
What are the two crafts underneath it all?
Being quotable is page-level work: answer-shaped writing, clean structure, schema markup, fast and crawlable pages. Being cited is entity-level work: consistent business details everywhere, reviews that corroborate what your site claims, and mentions on sources engines already trust. The two reinforce each other, and neither substitutes for the other. A quotable page from an unknown entity gets skipped; a known entity with unquotable pages gets summarized from someone else's description of it.
So what should you call it?
Use whatever the person across the table calls it. Arguing about acronyms mostly postpones the work, and the work stays much the same while the labels change. At Speak Local we gave up on the alphabet soup and organized everything under four pillars (Local, SEO, AEO and GEO) because those are the things a business can act on and measure. Learn the two crafts, track whether engines quote and cite you, and new acronyms (there will be more) will make sense the moment you see them.
