In one sentence: LLM optimization (LLMO), AI optimization (AIO), AI SEO, answer engine optimization (AEO) and generative engine optimization (GEO) are five names for one job, making your business retrievable and trustworthy to AI systems that answer questions, and the differences between them are mostly about which part of the machine the person naming it was looking at.
If you have been pitched by three agencies and each used a different acronym, this page is for you. I am going to lay every term on the table, tell you which ones are the same, and tell you where a real difference hides.
Why are there so many names for this?
Because the thing being named is new and the people naming it came from different places.
Search engine optimization has been a settled term since the late 1990s. When AI answers arrived on top of search (Google’s AI Overviews rolled out to everyone in the US on May 14, 2024),[1] the people who already did SEO needed a word for the new work. Nobody was in charge of picking it.
So SEO practitioners said “AI SEO.” Academics writing about how large language models cite sources said “generative engine optimization.” Marketers focused on the output said “answer engine optimization.” Software vendors, who like a category they can own, said “LLM optimization” or “AI optimization” or “AI visibility.” Each name stuck to the group that coined it.
None of this is unusual. When mobile overtook desktop (StatCounter measured the worldwide crossover in October 2016, 51.3% to 48.7%),[2] the industry spent a few years arguing over “mobile SEO,” “mobile-first,” “responsive” and “AMP” before settling. The vocabulary sorts itself out after the work does.
So what does each term actually mean?
Here is the map. I will give you the term, who tends to use it, what part of the machine it is named for, and my honest read on whether it is its own thing.
SEO, search engine optimization. Named for the search engine. The work of being crawled, indexed and ranked in the list of links. This is the base layer. Everything below sits on top of it because the AI systems retrieve from what search engines indexed.
AEO, answer engine optimization. Named for the output: an answer instead of a list. Used by marketers and by people who came from the featured-snippet era of Google. Means: be the thing the AI says back. Same job as GEO, different vantage point.
GEO, generative engine optimization. Named for the machine: a generative engine composes its reply rather than retrieving one. Used by academics, technical SEOs and people who want to sound precise. Means: be retrievable, consistent and cited when the engine generates. Same job as AEO.
LLMO, large language model optimization. Named for the model inside the engine. Used by software vendors and technical writers. Sometimes it is a synonym for GEO. Sometimes people use it to mean something narrower and, in my view, mostly mistaken: trying to influence what the model “knows” from its training, rather than what it retrieves at question time. Local answers are built from retrieval, not memory, so treat LLMO as GEO unless the person using it can explain the difference.
AIO, AI optimization. The vaguest of the set. Used by agencies as an umbrella for “anything to do with AI and marketing.” It is not a distinct discipline. When you see it, ask what specifically is being optimized. Note that Google itself uses “AIO” internally and in some coverage as shorthand for AI Overviews, which is a different thing entirely, so the same three letters can mean the Google feature or the agency service.
AI SEO. Plain-spoken and honest. Means SEO adjusted for the fact that AI answers now sit on top. Used by established SEO agencies. It is the same work as AEO and GEO with a name that reassures the buyer that it is still SEO underneath. WebFX, for example, sells an “AI SEO” retainer beginning at $3,000 per month.[3]
AI visibility. Not a discipline; a measurement. Whether and how often AI systems name your business. Vendors sell tools that track it (Otterly’s plans run $29 to $489 per month).[4] Think of AI visibility as the scoreboard and AEO/GEO as the game. It has its own page.
ASO, assistant search optimization (or “answer surface optimization”). A newer coinage for being findable through voice and chat assistants: Siri, Alexa, Gemini in Maps, Copilot. Most of the work is identical to GEO. The one real difference is that assistants often read a narrower set of sources (Apple Maps, Yelp, Google Business Profile) and often act rather than answer, booking or calling. Do not confuse it with “app store optimization,” the older ASO, which is about ranking apps in an app store and has nothing to do with this.
Conversational search optimization, chat search optimization, and similar. Marketing coinages. Same as AEO.
Which of these are actually the same thing?
AEO, GEO, LLMO (as usually used), AI SEO and “conversational search optimization” are one job under five names. Here is the test: what do you have to do to succeed at each?
For every one of them, the work is the same three things. Be retrievable: complete Google Business Profile, a website with one clear page per service naming the towns you serve, presence on the directories the engines read. Be consistent: identical name, address, phone, hours and services everywhere. Be corroborated: reviews that mention specific services and places.
That is not my opinion about what should work. It falls out of what the engines cite. In 1.9 million citations across local AI answers, Google Business Profile was 28.63% of citations, Yelp 9.53%, and business websites 42% of citations and 93% of unique domains.[5] Every acronym above is a name for being strong in those sources.
Where is the genuine difference?
Three places. They are worth knowing because they change what you would actually do.
Difference one: SEO versus everything else. SEO’s finish line is a position in a list. The AI terms’ finish line is being named in a composed answer. These are related but measurably different: only 19% of the sources cited inside AI Overviews overlapped with the organic top ten.[6] You can rank without being cited, and be cited without ranking. That is a real difference in outcome, so it deserves a separate name, and it has several.
Difference two: retrieval versus memory (the LLMO confusion). A generative engine has a trained model and a retrieval step. For a local plumber, the model has no memory of you. Everything it says comes from what it fetched seconds ago. Anyone selling “LLMO” as getting your business into the model’s training is selling something that does not apply to local businesses. Anyone selling it as retrieval work is selling GEO.
Difference three: answering versus acting (the ASO edge). Most AI terms assume the person reads the answer and then calls you. Assistants increasingly do the calling or booking. Google’s AI Mode already books restaurant and appointment slots through partners,[7] and Yelp reservations became bookable inside ChatGPT on August 10, 2026.[8] When the assistant acts, the sources it reads for availability and booking matter more than prose on your site. That is a genuinely different emphasis, though the foundation is the same.
Let me make it concrete with a plumber
You own a six-person plumbing shop in Roseville. Three agencies pitch you.
Agency one offers “AEO: we’ll get you in the AI answer.” Agency two offers “GEO: we’ll optimize for generative engines.” Agency three offers “LLMO: we’ll get your business into ChatGPT.”
Ask each one the same question: what will you change about my Google profile, my website and my reviews, and how will you measure whether ChatGPT and Google’s AI name me more often afterward?
If agencies one and two give you the same answer, which they should, they are selling the same thing under different labels. Judge them on the specifics and the measurement. If agency three says anything about “training” or “getting into the model,” ask how, because for a local plumber the honest answer is that they cannot, and the real work is the same retrieval work as the other two.
What all three should be measuring is the same thing: across a fixed set of realistic prompts (“emergency plumber Roseville,” “who fixes slab leaks near Roseville,” “best-reviewed plumber for water heater replacement in Roseville”), how often does each AI name you, and against whom? Today a tracked business is named in roughly a third of local AI answers (33% ChatGPT, 32% AI Mode, 38% AI Overviews) versus 66% on Google Maps.[5] Your number, before and after, is the only thing that settles which acronym was worth paying for.
What this is not
These terms are not competing technologies. They are competing vocabularies for one shift.
They are not a replacement for SEO. Every AI system retrieves from an index. A page that is not indexed cannot be cited under any acronym.
”AIO” is not always the agency service. In Google coverage, AIO usually means AI Overviews, the feature. Read the context.
ASO here is not app store optimization. Different field, same letters.
”AI SEO” is not “SEO done by an AI.” It means SEO adjusted for AI answers. Whether a human or a tool does the work is a separate question.
Where it is going
Forecasts, labelled as forecasts
Forecasts, stated as forecasts.
Forecast one: the vocabulary will collapse to two or three terms within a few years. My guess is that “SEO” survives as the umbrella, “GEO” or “AEO” survives as the name for the AI-answer layer, and “AI visibility” survives as the name for the score. LLMO and AIO fade because they describe the machine’s internals, which buyers do not care about.
Forecast two: the measurement will matter more than the label. As tools that track how often AIs name a business become cheap and common, buyers will ask for the number rather than the acronym.
Forecast three: “acting” will get its own term. As assistants book and call on the person’s behalf, being bookable through an assistant will become a distinct enough job to earn a name. Whether it is ASO or something else, I would not bet on the word.
What I do not forecast is that any of these replaces the base layer. Google reported search queries at all-time highs in 2026.[9] The list is still there; the answer sits on top of it. The acronyms describe the top. The foundation has the same name it has had for twenty-five years.