Not long ago, someone in a community thread asked (with an exhausted emoji) if anyone could please just explain AEO vs GEO vs AIO vs SEO. I don't blame them. In under three years, one discipline has picked up five names. One acronym ended up meaning two unrelated things, another was retired partway through, and job listings now ask for all of them at once.
That thread deserves a lasting answer, so this is mine. I'll cover what each term means and which ones are the same word, then which words I'd actually use.
The one-table answer
| Term | What it means | Status |
|---|---|---|
| SEO | Optimizing to rank in search results | The foundation, alive and well |
| GEO | Generative engine optimization: earning presence in AI-generated answers | The practice's research-lineage name |
| AEO | Answer engine optimization: the same practice, older lineage | Synonym of GEO in current usage |
| LLM SEO / LLMO | Informal umbrella for the same work | Synonym, SEO-community dialect |
| AIO (meaning 1) | Google's AI Overviews, and optimizing for them | A specific surface within the practice |
| AIO (meaning 2) | "AI optimization," generic vendor usage | Ambiguous; ask what they mean |
| SGE | Google's old experimental label for what became AI Overviews | Retired; dates the content using it |
| AI visibility | The outcome metric: your measurable presence in AI answers | The thing all the practices target |
If you're short on time, the table covers most of what people argue about. The backstory and corner cases below help when someone uses a term it doesn't cover.
GEO: the research-lineage name
GEO, generative engine optimization, is the one name here with a paper behind it. A 2023 academic study tested which content changes moved citation visibility in generated answers. The lifts you see quoted for adding statistics or quotations, or for citing sources, come from it.
The name stuck, I think, because it's accurate: an engine assembles its answer from other pages, and you want yours selected. GEO also has the most momentum right now, with entire strategy guides organized under it. If you need one word to standardize on internally, it's the easiest pick to defend.
AEO: the older lineage, same destination
Answer engine optimization dates from before the LLM era. It grew up around featured snippets and voice assistants, when the first "position zero" tactics were new and winning the answer box was the goal. Once AI answers arrived, the term moved over with the people using it.
Today AEO and GEO are the same job, and the two crowds differ mostly in emphasis. AEO people bring up question-shaped content and structured answers, GEO people bring up citations and entity trust, and both camps end up shipping the one playbook that survived. Treat them as synonyms. If a proposal lists AEO and GEO as separate line items, you're paying two fees for one piece of work.
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LLM SEO and LLMO: the dialect of SEO teams
You don't need a glossary for LLM SEO, since the name says it: SEO, pointed at LLMs. SEO-first teams like it because anyone who thinks in search terms gets it at once. LLMO, short for large language model optimization, is the same idea in a tidier package. Neither one came out of research, and both work fine as labels.
The term is also a clue about who's using it. A team that says LLM SEO usually sees the work as search discipline stretched to a new channel, which is mostly right. Now and then it walks them into the classic mistake, which I call the one-playbook trap: one plan run across engines that have almost nothing in common.
If you've settled on the term and want the playbook, our LLM SEO strategies built from what ChatGPT searched cover the practical side.
AIO: the acronym with two jobs
This acronym causes most of the mix-ups, because it has two meanings and you need to know which one the speaker has in mind.
Used precisely, it's Google's AI Overviews, the AI summary above the results, and "AIO optimization" means earning presence and citations in that specific surface. It's real work, with measurement headaches of its own. Used loosely, mostly by vendors, AIO just means "AI optimization," a marketing label stretched over the whole practice.
When a job listing asks for "SEO, GEO, AIO expertise," I'd bet it means the Google surface. An "AIO score" in a tool's pitch could be measuring anything, so ask, because the two meanings come with different scopes and budgets. ASO has the same problem, since app store optimization shares its three letters with several AI meanings, and our piece on AI search optimization vs ASO sorts those out.
The retired cousin is SGE (Search Generative Experience), Google's name during the experiment, before the feature shipped in 2024 as AI Overviews. If an article still leads with SGE, you know roughly when it was written, the way "Bing Chat" gave away a post's age once the name changed to Copilot.
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One timeline explains the mess
Nobody set out to confuse you. Three communities named the same new thing at once, and no one ever got them in a room to agree.
The SEO world had AEO first, from the answer-box era, when featured snippets and voice assistants made "position zero" worth chasing years before any engine generated an answer. Researchers coined GEO in 2023 with the paper that measured citation-visibility lifts, the first real evidence anyone had for the practice. That same year, mainstream SEO met ChatGPT, grabbed the closest label it already knew, and got LLM SEO and LLMO.
Google, meanwhile, renamed its feature in public. SGE was the experiment, what shipped was called AI Overviews, and AI Mode became the fuller surface. The industry shortened the shipped feature to AIO right when vendors began using those letters for "AI optimization" in general, which is how one acronym got two jobs.
I'd expect the labels to merge, since young fields usually spend a few clumsy years like this before settling. By 2026, everyone was already doing the same work under different names.
The skeptics' corner, answered
Post in any terminology thread and you'll get the same reply, usually ruder than this: it's all SEO with a new name so agencies can charge more. It deserves a real answer, because it's half right.
Google's own line is that its AI features need nothing beyond ordinary SEO, and the foundation doesn't change with the acronym. Content still has to be crawlable and well structured, and it still has to be trustworthy. If a vendor's GEO report reads like last year's SEO report with new headings, the skeptics are right about that vendor.
The other half fails, and you can measure it. On some engines the domains that get cited have only a weak overlap with Google's top ten, and across engines the overlap nearly disappears. What decides answer selection, passage extraction, entity trust, per-engine divergence, pays off for work that classic SEO never put first. So I hold both views, a shared base with a new selection layer on top, and any acronym is fine with me if that layer gets its own line on the bill.
Five vocabulary mistakes that cost real money
Vocabulary costs nothing in conversation, but it gets expensive in a contract or a job listing. These are the five mistakes I'd watch for.
Buying AEO and GEO as separate services tops my list, since that's one practice billed twice. Next is an AIO contract that never says which AIO it means. Google's feature and the generic umbrella have different scopes, so the statement of work has to name one of them. Content that still says SGE is a quieter trap, because that label retired in 2024 and the page hasn't been updated since.
Then there's hiring off a stack of acronyms. An "SEO, GEO, AIO expert" listing filters for people who know the words, so interview for the practice and ask what numbers they check weekly. And don't accept a score because a practice name is on it. If a proprietary "GEO score" can't be split by engine, you can't tell which engine moved it.
The word that actually matters: AI visibility
Set the practice names aside and one distinction still matters: what you do versus what you measure. GEO, AEO, LLM SEO and AIO (either kind) are all things you do. AI visibility is what you measure. It counts how often each engine mentions or cites your brand, and how favorably it describes you, tracked over time.
Keep the two apart and a vendor can't sell you a practice word with no result tied to it. Whatever your team calls the work, Monday's question doesn't change. Did your presence in the answers move? If it did, you want to know where and why, and which competitor it moved against. That question has a per-engine answer, and it's why the scoreboard we build exists, since the acronyms kept multiplying and hardly anyone was measuring the result.
How to talk so people understand you
So which word should you use? This is the style guide we work by every day. Pick one practice term internally and stick with it. Ours is GEO, which is also the industry's current favorite. Say "AI Overviews" in full when you mean Google's feature, and keep AIO for audiences you know read it the precise way.
With everyone else, match the listener. The search team gets LLM SEO, the answer-box veterans get AEO, and the industry deck says GEO. The board gets "showing up in AI answers," since no board has ever cared which acronym came out on top. When a vendor opens with an acronym you haven't heard, ask which engines they cover and which metric their work moves. With those two answers you can compare them to anyone else, whatever acronym they led with.
These labels will keep changing while the practice keeps converging, so the decision framework between the disciplines deserves more of your attention than any of them. Once you have the map, talk in your audience's words and put the saved time into the part that compounds: getting the answers to know your brand.
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