SEO: being ranked
Search Engine Optimization is the classic discipline: earning a high position in the list of links Google and Bing return. It rewards relevance, authority, internal linking, page speed, and keyword coverage. SEO still matters, it is how engines find and evaluate you in the first place.
GEO: being cited
Generative Engine Optimization is about being used as a source when an AI engine like ChatGPT, Claude, Gemini, or Perplexity composes an answer. The engine reads many pages and cites a few. GEO rewards factual density, quotable statements, clear sourcing, and structured data, the signals that make your content easy to lift into an answer.
AEO: being the answer
Answer Engine Optimization targets the single direct response: the featured snippet, the AI Overview summary, the one-line assistant reply. AEO rewards concise definitions, question-shaped headings, and schema, content shaped so an engine can answer with it verbatim.
Why you need all three
The same page serves all three layers, but a page can win one and lose the others: ranked first yet never cited, or cited by AI while invisible in traditional results. That is why RankAbove scores the three side by side, and why fixing the weakest layer usually delivers the fastest visible gain.
Rule of thumb
SEO gets you considered. GEO gets you quoted. AEO gets you to be the answer itself.