AEO is optimizing content so answer engines — AI systems that reply with a direct answer instead of a list of links — surface and cite your brand.
The term predates the LLM era (featured snippets and voice assistants were the first answer engines), but it now overlaps heavily with GEO. The distinction most practitioners draw: AEO focuses on being the cited source of an answer; GEO focuses on being the recommended brand inside the answer.
In practice the two converge, because models like Perplexity build recommendations directly from the sources they retrieve. Content structured to be quotable — clear claims, real data, honest comparisons — serves both.