AEO vs GEO vs SEO: What Each One Actually Means

Three acronyms are competing for space in every marketing plan this year, and most of the writing about them is circular. Here are the plain definitions, the metrics that belong to each, and an honest answer to which one you need.

The one-sentence versions

SEO — Search Engine Optimization. Getting your page to rank in a list of links.

AEO — Answer Engine Optimization. Getting your content selected as the source an answer engine uses when it needs a fact, a definition, or a recommendation.

GEO — Generative Engine Optimization. Shaping how generative AI systems represent your brand overall — whether you are named, how accurately you are described, and how you are positioned against competitors.

The distinction that matters: SEO competes for a position. AEO competes to be the source. GEO competes for the description itself.

How they relate

The cleanest way to hold this is that AEO is a layer inside GEO, and SEO is an adjacent discipline that feeds both without covering either.

AEO is narrow and mechanical. When an assistant assembles an answer it retrieves supporting material, and AEO is the practice of being what gets retrieved and cited. It is largely about your own content: structure, clarity, factual density, machine-readability, freshness.

GEO is broader and much less under your control. A model’s picture of your brand is assembled from your site, yes — but also from review platforms, Reddit threads, press coverage, directory listings, comparison pages written by competitors, and whatever was in its training data eighteen months ago. You can win AEO comprehensively and still lose GEO, because the model can cite your pricing page for a fact while describing your company using an outdated summary it absorbed from somewhere else entirely.

SEO still matters, but it stopped being sufficient. Traditional ranking signals — backlink authority, keyword targeting, click-through rates — do not translate cleanly into AI answers. An assistant does not rank pages. It synthesises. A page that ranks fourth on Google can be the sole cited source in an AI answer, and the page that ranks first can go unmentioned.

The pressure to care about this is not theoretical. Similarweb has measured zero-click search rates rising from 56% to 69% since AI Overviews launched, and Gartner has projected a 25% decline in traditional search volume as assistants absorb the queries. The traffic is not disappearing; it is being answered before it reaches you.

The metrics that go with each

This is where the three disciplines separate most clearly, and it is worth learning the AI-side vocabulary properly — the industry standardised on these terms during 2026 and you will see them in every tool.

SEO metrics: average position, impressions, clicks, click-through rate, organic sessions.

AEO metrics:

• Citation rate — the share of relevant AI answers that cite your site as a source.
• Prominence — when you are cited, how much of the answer traces back to you and where in the response you appear. Third source in the closing paragraph is not the same as the basis of the opening sentence.

GEO metrics:

• Mention rate — how often your brand is named in answers, whether or not your site is cited. The gap between mention rate and citation rate is diagnostic: high mentions with low citations means the model knows you but is learning about you somewhere else.
• Share of voice — your presence relative to competitors when the category is queried. If a buyer asks for “the best” in your market, how often are you in the answer, and in what order?
• Sentiment — whether the description is favourable, neutral, or quietly damaging.
• Accuracy — whether what the model says is true. This one has no analogue anywhere in SEO, and it is the one that costs real money. A model confidently quoting a price you stopped charging two years ago is not a ranking problem.

Which one do you need?

You need AEO if your buyers ask assistants factual and comparative questions your content could answer — “how does X work”, “what’s the difference between X and Y”, “best tool for Z”. AEO work is concrete and largely within your control, which makes it the best place to start.

You need GEO if your brand is discussed in AI answers whether or not you participate. This is true of essentially every company with customers, and it is more urgent the less of your reputation lives on your own domain — apps, local businesses, consumer brands, anything with an active review presence.

You still need SEO because your own pages remain the most authoritative and correctable input into both. Fixing your own site is still the highest-leverage move available.

In practice: if you have a content team, they should be doing AEO. If you have a brand, someone should be watching GEO.

What actually moves each one

For AEO, the work is structural:

• Answer real questions directly, in the first two sentences, before the context and caveats.
• Keep facts unambiguous and specific. Models retrieve claims, not vibes.
• Publish clean definitions of the terms in your category — definition content is disproportionately cited.
• Make the machine-readable version easy to get: clear headings, structured data, and plain-markdown twins of your pages if you can serve them.
• Keep it current. Stale pages get retrieved less and misquote you more.

For GEO, the work is mostly off your own site:

• Audit the sources models actually draw from: review platforms, Wikipedia, Crunchbase, industry directories, Reddit, comparison articles.
• Fix the inconsistencies between them. Models synthesise conflicting signals into confident errors.
• Write down a plain-language factual record of what you are, who you serve, and what you explicitly are not — then make sure every public source agrees with it.
• Watch what competitors are publishing about you. Comparison pages they write become the model’s summary of you.

Where measurement fits

Both disciplines are unmeasurable by intuition. You cannot infer your mention rate from your own experience of using ChatGPT twice, and a manual audit every quarter gives you a lagging indicator of something that changes weekly.

The practical split: AEO metrics can be checked periodically, because citation patterns move slowly and the fixes are slow too. GEO metrics need continuous watching, because accuracy and sentiment can break suddenly — a model update, a bad review cycle, a competitor’s new comparison page — and the cost of finding out three months late is not symmetrical with the cost of finding out the same day.

Which is the real difference underneath the acronyms. AEO asks is my content being used. GEO asks is the story about me still true. The first is a project. The second is a standing obligation.