SEO, AEO, and GEO describe three different outcomes in search. SEO (search engine optimization) competes for a ranking position in a list of links, where the reward is a click. AEO (Answer Engine Optimization) competes for the answer slot itself, where the reward is being the source an engine quotes, whether or not anyone clicks. GEO (Generative Engine Optimization) competes for a mention inside AI-generated answers across engines such as ChatGPT, Perplexity, Gemini, Google AI Overviews, and Google AI Mode, where the reward is being on the shortlist the user is handed. The three sit on a shared foundation and diverge in what counts as winning.
The short version
| SEO | AEO | GEO | |
|---|---|---|---|
| Competes for | A position in a list of links | The extracted answer | A mention inside a generated answer |
| Unit of success | Rank for a query | Your content used as the answer | Brand named, cited, described correctly |
| Main surface | Traditional results page | Snippets, People Also Ask, AI summaries | Multi-engine AI-generated answers |
| Scope of control | Your pages plus authority signals | Mostly your pages | Your pages plus every source the engine reads |
| What the user does | Scans and clicks | Reads the answer, may not click | Acts on a shortlist they did not assemble |
The row that matters most is scope of control. SEO and AEO are largely won on a brand's own pages. GEO is not, because AI-generated answers lean heavily on third-party sources, so a brand's presence depends partly on what other people have published about it.
SEO
SEO optimises for position in traditional search results. The work is well established: keyword research, content built against target queries, technical health, internal linking, and the third-party links that signal authority. The measurement is mature and the feedback loop is slow but legible, since a ranking is a stable thing that can be checked.
Everything the other two disciplines rely on is built here. A site that cannot be crawled, has thin content, or is never referenced elsewhere will not rank, and will also not be extracted or cited. SEO is the foundation layer rather than a competing option.
AEO
AEO optimises for being the source an engine takes its answer from. It grew out of SEO when featured snippets and People Also Ask began answering questions directly on the results page, which meant a brand could rank first and still lose the interaction to whichever source got quoted.
The levers are page-level: state the answer at the top of the section rather than building to it, phrase headings as the questions people actually ask, make claims specific enough to be quotable, mark up the page so its structure is explicit, and give the engine clean units to lift such as tables and scoped FAQ entries. Because the work is mostly restructuring content that already exists, AEO is usually the cheapest of the three to add. See what AEO is for the detail.
GEO
GEO optimises for presence inside AI-generated answers. The question is not whether a page ranks or gets extracted, but whether the brand is named at all when someone asks an AI engine a category question, and whether the description attached to it is accurate.
Two things make this different from the other two. The first is that answers are generated rather than retrieved, so the same question can produce different answers on different runs and different answers on different engines. Visibility on one engine says little about visibility on another. The second is that the source pool is largely external. Review sites, forums, comparison articles, and industry press feed these answers, which means a share of GEO outcomes depends on content the brand does not own and cannot edit.
That external dependency is why GEO needs its own measurement. A brand can confirm its rankings and confirm its pages are well structured, and still have no idea whether it appears when a buyer asks an AI engine which brands to consider. See what GEO is for the detail, and GEO vs SEO for a closer two-way comparison.
Where the three overlap
Most of the underlying work is shared. All three need a site that engines can reach and parse, content that answers real questions with checkable specifics, and third-party sources that reference the brand. Schema markup, clean HTML, sensible site structure, and crawler access rules serve all three at once.
This is why treating them as separate budgets tends to waste effort. The foundation is one body of work. What differs is which outcome you look at afterwards, and therefore what you measure.
Which one a brand needs first
The useful starting question is where the category's buyers are actually discovering brands.
If buyers still search, compare across tabs, and click through, SEO carries the most weight, and AEO is the obvious next increment because it mostly restructures pages that already exist.
If a growing share of buyers are asking conversational questions and acting on the shortlist an AI hands back, GEO measurement moves up. The reason is diagnostic rather than tactical: until a brand measures what AI engines say about it, it cannot tell whether it is absent from those answers, present but described wrongly, or present and doing fine.
Most brands end up needing all three. The sequencing follows category behaviour, not a fixed order.
Related terms
Answer slot. The position on a results page where an engine presents a direct answer rather than a link.
Extraction. An engine taking a specific passage, table, or fact from a source to use in an answer.
Grounding. Anchoring a generated answer in retrieved source material rather than model memory, which is what makes citation possible.
Share of voice. The share of category mentions in AI answers belonging to one brand. See share of voice in AI search.
Citation. A source link attached to an AI-generated answer.
Key Takeaways
- SEO competes for a ranking, AEO competes for the extracted answer, and GEO competes for a mention inside AI-generated answers
- The three share one foundation: crawlable pages, content that answers real questions with specifics, and third-party sources that reference the brand
- Scope of control is the sharpest divider, since SEO and AEO are won mostly on your own pages while GEO depends heavily on sources you do not own
- AEO is usually the cheapest addition because it restructures content that already exists rather than creating new content
- GEO needs separate measurement because AI answers are generated fresh each time and vary between engines, so one engine tells you little about another
- Sequencing follows where your category's buyers are actually discovering brands, not a fixed order across the three