Short definition
Answer Engine Optimization is the practice of structuring content so it can be lifted directly as the answer in AI assistants, voice search, and featured snippets.
In depth
AEO overlaps heavily with structured SEO but focuses specifically on the question-answer transaction: a user asks a natural-language question and expects a concise, sourced response. AEO requires writing in question-and-answer form, leading important pages with a clear answer, deploying accurate schema where appropriate, ensuring statistics carry sources, and cross-linking related answers.
Example
A site adds an /answers/ section with one URL per buyer question. Within months, several entries are read aloud by Google Assistant and Alexa for the same queries.