SEO and AI search, defined.

SEO (Search Engine Optimization) is optimizing for Google/Bing’s organic results. GEO (Generative Engine Optimization) is structuring content to be cited by AI engines like ChatGPT and Perplexity when they generate an answer. AEO (Answer Engine Optimization) targets direct-answer surfaces — Google AI Overviews, Bing Copilot, featured snippets. “AIO” is used inconsistently across the industry — sometimes as a synonym for GEO, sometimes for AI Overview optimization specifically — so we avoid it and use GEO/AEO, which have clearer, more consistent definitions.

AEO targets structured direct-answer surfaces with a defined format — Google AI Overviews, Bing Copilot, featured snippets — where concise, well-marked-up answers win a slot. GEO targets open-ended generative responses from AI assistants like ChatGPT, Claude, and Perplexity, where there’s no fixed answer box and the model decides what to cite based on how clearly your content demonstrates authority on the topic. In practice the two overlap: content built for GEO (clear structure, direct answers, credible sourcing) usually performs well for AEO too.

AI assistants cite sources they judge authoritative and easy to extract a clear answer from — not necessarily the sites that rank #1 on Google. That means clear, direct-answer content (this glossary’s format is a deliberate example), consistent factual claims across your site, structured data (FAQPage, DefinedTerm, Organization schema), and a presence on the third-party sites AI models already trust (review sites, comparison pages, forums). SearchChamp’s AI Visibility tracker shows exactly which prompts cite you today across all 8 engines, so you can see what’s working before changing anything.

Every definition on this glossary is free to read — no account, no trial, no paywall. Where a term maps to a SearchChamp feature (like AI Visibility or llms.txt), we link to that tool’s page, which does require an account (7-day free trial, credit card required) to run against your own site.