For GEO, the answer engine is the destination. ChatGPT, Perplexity, Google AI Overviews, Microsoft Copilot, Gemini, and Claude all qualify. They share a common property that flips the SEO contract: ranking on the SERP no longer guarantees the click. GEO is the discipline of being represented in the answer itself, not just the page beneath it.
GEO glossary
Answer engine
An answer engine is an AI system that synthesises a direct answer to a user query, typically grounded by retrieved sources, instead of returning a ranked list of links.