A few years ago there was one acronym that mattered: SEO. Get your pages to rank in Google and the work was done. Now there are three, and the newer two, AEO and GEO, exist because the way people find answers has changed underneath the old model. Understanding the difference is not academic. It decides where your effort should go and what a supplier should actually be doing for your money.

The short version: SEO earns a ranking. AEO earns the answer. GEO earns the citation. They rest on the same foundations, but they aim at three different moments in how a customer now finds you.

SEO — Search Engine Optimisation

SEO is the discipline you already know. It works to place your pages as high as possible in a list of search results, so that when someone searches, you appear near the top and they click through to your site. It rewards clean technical foundations, relevant content, page speed, and trusted links from other sites.

SEO still matters, because a large share of searches still return a list of links, and Google still sends real traffic. It is the base layer. But ranking first in a list is no longer the only outcome worth pursuing, because for a growing share of searches, the list is not what the customer sees first.

AEO — Answer Engine Optimisation

AEO shifts the goal from being ranked to being chosen. When someone asks a direct question, of Google, of a voice assistant, of a search box that now answers rather than lists, the system tries to return a single answer rather than ten options. AEO is the work of making your business that answer.

This rewards content shaped like questions and answers, clear and unambiguous facts, structured data that labels what each part of a page means, and business information that stays consistent everywhere it appears. Where SEO competes for a position, AEO competes to be the one response the system is confident enough to give.

GEO — Generative Engine Optimisation

GEO is the newest, and it targets the generative AI systems now sitting in front of search: ChatGPT, Perplexity, Google's AI Overviews, Gemini. These don't return a list at all. They write an answer and, increasingly, cite the sources they drew on. GEO is the work of being one of those cited sources, of being named when the machine speaks.

This is a different game because AI systems don't just index pages, they build a model of who a business is, what it knows, and whether it can be trusted. Being cited depends on whether your site can be read cleanly by a machine, whether your identity is consistent across the web, and whether you have demonstrated genuine authority in your field. It is the subject of our Periodic Table of Digital Authority, which organises the signals AI search uses to find, read, trust and cite a business.

The one-line distinction

SEO gets you into the list. AEO gets you chosen as the answer. GEO gets you named inside the AI's response. Same foundations, three different finish lines.

How they compare

 SEOAEOGEO
GoalRank in the listBe the chosen answerBe cited in the AI response
Where it showsGoogle results pageAnswer boxes, voice, featured answersChatGPT, Perplexity, AI Overviews, Gemini
The prizeA clickThe single answerA citation and brand mention
Leans onContent, links, technical healthQ&A structure, schema, clear factsEntity clarity, machine-readability, authority
Still matters?Yes, base layerGrowing fastThe new frontier

Which one does your business need?

The honest answer is usually all three, because they draw on the same underlying foundations, technical health, clear content, structured data, consistent identity and real authority. Improve those and you lift all three at once. The reason to name them separately is diagnostic: it tells you where your biggest gap sits right now.

If you rank in Google but never appear in ChatGPT, your gap is GEO. If you have great content that never gets chosen as the direct answer, your gap is AEO. If you are barely visible anywhere, the foundation, SEO, needs attention first. The mistake is paying for one while your gap is in another, which is why the work should start with measurement, not a package.

Common questions

What is the difference between SEO, AEO and GEO?

SEO works to rank your pages in a list of results. AEO works to have your business chosen as the direct answer a system gives. GEO works to have your business named and cited inside AI-generated answers such as ChatGPT, Perplexity and Google's AI Overviews. They share the same foundations but aim at three different outcomes: a ranking, an answer, and a citation.

What is GEO (Generative Engine Optimisation)?

GEO is the practice of getting a business understood, trusted and cited by generative AI systems. Where SEO targets a position in a ranked list, GEO targets being named as a source inside an AI-written answer. It depends on machine-readable structure, consistent entity signals and demonstrated authority rather than link counts alone.

What is AEO (Answer Engine Optimisation)?

AEO is the practice of getting your business selected as the direct answer to a question, rather than one link among many. It matters most for question-shaped searches and voice queries, and relies on clear structure, question-and-answer formatting, schema markup and consistent business information.

Do I need SEO, AEO or GEO?

Most businesses need all three, because they share the same technical and content foundations. SEO builds rankings in Google, AEO gets you chosen as the answer, and GEO gets you cited in AI-generated responses. The right starting point is a diagnostic that shows which of the three has the biggest gap for your business.

Find your gap first.

Book a diagnostic with Doug to see where you stand across SEO, AEO and GEO, and which one to fix first, before you spend on any of them.

Book Diagnostic →
About the author
Douglas Lord
Digital Authority & AI Visibility Strategist · Founder of Digital Dominator · Creator of PTODA

Doug Lord is a Digital Authority & AI Visibility Strategist and founder of Digital Dominator. He created the Periodic Table of Digital Authority™ (PTODA), an independent research framework for measuring digital authority, AI visibility and crawler accessibility, and is co-founder of OG01, where he serves as COO and CPO.

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