SourceCited / Glossary
Reference · Glossary
SEO, AEO, GEO, AIO, LLMO, "AI SEO" — the same idea under many names. Here's what each one means and how the pieces fit.
The terms are used interchangeably. GEO (Generative Engine Optimization) is the umbrella most practitioners mean; AEO is its on-page, single-answer half; AIO, LLMO, and "AI SEO" are synonyms. All describe getting your content cited by AI answer engines — the "AI equivalent of SEO."
There's no single agreed name — the field is called GEO, AEO, AIO, LLMO, and "AI SEO" more or less interchangeably, and no consensus definition separates them in the academic literature yet. In practice, GEO (Generative Engine Optimization) is the umbrella term most practitioners use for making your content citable by AI answer engines, with AEO as the on-page, single-answer half of it. If someone asks for the "AI equivalent of SEO," this cluster of terms is the answer.
| Term | Stands for | What it means |
|---|---|---|
| SEO | Search Engine Optimization | Ranking in the classic list of links. The foundation everything else builds on. |
| GEO | Generative Engine Optimization | Getting cited inside AI-generated answers (ChatGPT, Perplexity, AI Overviews, Gemini, Claude). |
| AEO | Answer Engine Optimization | Structuring a page to be the single extracted answer — the featured snippet's AI descendant. |
| AIO | AI Optimization | Catch-all synonym for GEO/AEO; also "AI Overviews" as a Google feature. |
| LLMO | LLM Optimization | Same idea, framed around large language models specifically. |
| AI SEO | — | The plain-language name most people search; means all of the above together. |
Consensus engine. How AI search behaves: it favors facts that multiple independent sources agree on, which is why off-site mentions matter as much as your own page.
Citation. Being named as a source inside a generated answer — the goal of GEO. Distinct from a click.
AI Overview. Google's AI-generated summary at the top of results, appearing on roughly half of tracked queries.
Earned media. Third-party pages that mention you (Reddit, listicles, reviews, press) — the source of the large majority of AI citations.
Entity. A recognizable person, product, or organization a model can identify and reference confidently. Clear entity signals raise citation likelihood.
Information gain. Original data, testing, or facts a page adds beyond the existing consensus — what earns citations instead of rehashing.
Share of voice. How often you appear across a set of AI answers versus competitors — the core AI-visibility metric.
Zero-click. A search resolved inside the answer with no outbound click; the reason being cited now matters more than being merely ranked.
llms.txt. A Markdown file at your domain root mapping your key pages for AI agents. Agent-readiness, not a citation lever on its own.
Agentic browser. A browser whose AI agent acts on pages — clicks, fills forms, completes tasks — for the user (ChatGPT Atlas, Perplexity Comet, Copilot Mode in Edge). It parses your accessibility tree, not your pixels.
WebMCP. A W3C draft letting a page expose callable tools to in-browser agents instead of being scraped. Emerging (Chrome origin trial); already checked by Lighthouse.
Ghost citation. An AI answer citing your URL without naming your brand — a major reason AI visibility under-counts in name-based tracking.
Most commonly GEO (Generative Engine Optimization) or AEO (Answer Engine Optimization), with AIO, LLMO, and "AI SEO" used as synonyms. No single term has won; they all mean optimizing to be cited by AI answers.
They overlap heavily. GEO is the broad goal of being cited across generative engines; AEO is the narrower, on-page craft of being the single extracted answer. In everyday use people treat them as interchangeable.
There isn't one clean replacement — it's this family of practices (GEO/AEO/AIO/LLMO). And it doesn't replace SEO; it stacks on top, because strong classic SEO is still the foundation AI visibility is built on.