The short answer. SEO earns a page a position in a list of results. Answer engine optimization (AEO) makes sure the right question has a page whose first lines answer it. Generative engine optimization (GEO) makes the content of that page quotable: specific, sourced, dated and original. All three draw on the same web index, so none of them replaces the others. Most sites with an AI-visibility problem have an SEO problem underneath it.
This article defines each term, shows where they overlap, and gives a way to tell which one a given symptom needs.
What is SEO?
Search engine optimization is the work of making pages crawlable, indexable, understandable and worth ranking for the queries people type. Google’s SEO starter guide still describes the whole of it: let Google find and read the pages, organise the site, write useful titles and content, and earn links and mentions.
What SEO changes: whether a page is in the index, how it is understood, and where it appears in the list for a query.
What it does not change on its own: whether an assistant quotes the page. A page can rank first and never be cited, because being retrieved and being quoted are different steps.
What is AEO?
Answer engine optimization starts from questions rather than keywords. The work is a question map (what people ask, grouped by intent and stage), a page for each question that matters, and a structure that puts the answer first: the question as the heading, the answer in the first sentence, the specifics and the source immediately after.
Google’s AI features documentation says there is no special markup for AI Overviews or AI Mode; eligibility follows the normal indexing and snippet rules. What the engines can lift is a passage that stands on its own, which is exactly what answer-first structure produces. The same structure earns featured snippets.
What AEO changes: coverage (is there a page for the question) and extractability (can the answer be lifted cleanly).
What it does not change: whether the claim inside the answer is strong enough to be chosen over another site’s. That is GEO’s job.
What is GEO?
Generative engine optimization is about the evidence inside the page. Systems that generate answers pick passages they can defend: a specific claim, a named source, a visible date and author, and something original rather than a restatement of what every competitor says. Google’s helpful content guidance lists the same qualities for ordinary ranking, which is one reason the three disciplines keep converging.
What GEO changes: how often a retrieved page is actually quoted, and whether the quote is accurate.
What it does not change: whether the page was retrieved in the first place. If the crawler cannot reach it, or the site is not in the engine’s index, no amount of citability helps. OpenAI, for example, documents a separate crawler for ChatGPT search, OAI-SearchBot; if it is blocked, the content is not available to be quoted. Perplexity documents the same split between PerplexityBot and Perplexity-User.
SEO
- Whether a page is in the index
- How it is understood
- Where it appears for a query
Not on its own: whether an assistant quotes the page
AEO
- Coverage: a page for each question
- Extractability: an answer that can be lifted cleanly
Not on its own: whether the claim is strong enough to be chosen
GEO
- How often a retrieved page is quoted
- Whether the quote is accurate
Not on its own: whether the page was retrieved in the first place
Where do the three overlap?
Almost everywhere that matters.
| Task | SEO | AEO | GEO |
|---|---|---|---|
| Crawlable, indexable pages | Yes | Depends on it | Depends on it |
| Clear site structure and internal links | Yes | Yes | Indirectly |
| One page per question | Partly | Yes | Indirectly |
| Answer in the first sentence | Helps | Yes | Yes |
| Specific, sourced claims | Helps | Yes | Yes |
| Visible author and date | Helps | Helps | Yes |
| Original data or examples | Helps | Helps | Yes |
| Consistent entity facts | Yes | Yes | Yes |
The honest reading of that table is that AEO and GEO are mostly good SEO with the emphasis moved from the query to the question and from the page to the passage. Treating them as separate budgets, separate vendors or separate dashboards usually produces three teams rewriting the same pages.
Which one does a given symptom need?
Work from the symptom, not the label.
- “Our key pages are not indexed” or “traffic fell after a redesign.” SEO, specifically the technical side. Nothing downstream will fix a page the crawler cannot read.
- “We rank, but assistants never mention us.” Usually two things at once: entity clarity (does the system know who you are) and citability (is there a passage worth quoting). That is GEO plus entity work, with a crawler-access check first.
- “Assistants describe us wrongly.” Entity work. The facts on the site, on profiles and in structured data disagree with each other or with what the system has learned elsewhere.
- “We have no page for the questions buyers ask.” AEO. Start with the question map.
- “We publish a lot and none of it gets cited.” GEO. The content is probably accurate but generic: no numbers, no sources, no author, nothing original.
How do you measure each one?
SEO has mature measurement: Search Console impressions, clicks and position by query and page. AEO can borrow some of it: AI Overview and AI Mode impressions appear in Search Console’s Generative AI performance report, and Bing Webmaster Tools reports citations in Copilot. GEO has the least first-party data, because most assistants publish no site-level report. For those, a sampling method is the only repeatable option: a fixed prompt set, several runs, and mention, citation and accuracy rates with the spread shown.
What we don’t claim
- We do not claim that any of the three guarantees a mention, a citation or a ranking. None of the vendor documentation linked above offers such a mechanism, and neither do we.
- We do not claim the labels are stable. Vendors and agencies use AEO and GEO with overlapping meanings; the definitions above are the ones we use, stated so you can check our work against them.
- We do not claim AI assistants are a larger source of traffic than classic search for any given site. Measure it. Our AI referral segment tool sets up the report.