What is the difference between AEO, GEO, and SEO?

The three terms side by side

SEO, Search Engine Optimization, is the oldest and most established of the three: improving a page's position in a ranked list of links on a results page, targeting engines like Google's and Bing's core web search. Success looks like a rank position, third, first, page two.

AEO, Answer Engine Optimization, targets whether a page is selected to form a direct answer, spoken or written, rather than one link among many. It covers voice assistants, featured snippets, and AI Overviews alike. Success looks like a yes-or-no outcome: named in the answer, or not.

GEO, Generative Engine Optimization, targets whether and how a page's content is retrieved and woven into a generative AI system's synthesized response specifically. It was formally defined in a 2024 research paper as "the first novel paradigm to aid content creators in improving their content visibility in generative engine responses" (Aggarwal et al., 2024), with its own benchmark for measuring visibility inside generative answers.

Where they overlap and where they genuinely differ

In practice, the same underlying work, a crawlable site, accurate structured facts, and clear, direct language, helps all three at once, so the terms function more as different lenses on the same quality signals than as three unrelated disciplines each requiring separate execution. Where they differ is in what counts as success and what mechanics they depend on. SEO's unit of success is a rank position on a page of links. AEO and GEO's unit of success is inclusion in a generated answer at all, with no position to hold once you are in it. GEO specifically concerns itself with the retrieval and synthesis mechanics of generative models, covered in more depth in our generative engine optimization definition, while AEO is the broader umbrella covering any direct-answer output, including non-generative ones like a classic voice assistant snippet pulled from a single ranked page.

GEO in an SEO context

Within ordinary SEO conversation, "geo" is also common shorthand for "geographic," as in geo-targeting a specific city or a geo-modifier keyword such as "plumber near me" or "dentist in Springfield," a decades-old local SEO concept entirely unrelated to generative AI. When a local business owner searches for "geo SEO," they most often mean geographic or local targeting, not generative engine optimization. Context, and often the fuller phrase "generative engine optimization" attached, is what distinguishes the two uses of the same three letters.

AIO

"AIO," short for AI Optimization, is a catch-all some practitioners use for optimizing content for AI systems broadly, without the research grounding GEO has or the answer-specific framing AEO has. It has no single authoritative definition or academic origin. Most people using it mean the same general goal as AEO or GEO: being found, understood, and cited by AI systems, phrased with a broader, less specific label.

LLMO

"LLMO," short for Large Language Model Optimization, is another informal synonym, occasionally used to mean optimizing content specifically for large language models like GPT and Claude rather than for narrower features like Google's AI Overviews. Like AIO, it lacks a single authoritative definition and functions as a stylistic preference among certain writers more than a distinct methodology, generally interchangeable with AEO and GEO in day-to-day use.

Why the distinction matters to a local business

You do not need to pick exactly one of these to focus on. A veterinary clinic working through SEO fundamentals, crawlable pages, accurate content, reasonable load times, is already most of the way toward AEO and GEO readiness too, since none of the three works without that foundation. Treating them as one connected effort, rather than three competing projects, is both more accurate to how the underlying mechanics actually work and a better use of a small business's limited time.

What to do about it

• Do the foundational SEO work first: a crawlable site, fast pages, and accurate content, since AEO and GEO both assume it.
• Layer in structured data and plain, direct-answer writing for AEO; see answer engine optimization for specifics.
• Write specific, quotable, well-sourced facts for GEO's retrieval and synthesis mechanics; see generative engine optimization.
• Confirm the AI-specific crawlers that matter can actually reach your site; see AI crawlers.
• Measure outcomes across all three with a real check rather than assuming success; see AI visibility.