> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getcited.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Answer Engine

> An AI platform that generates synthesized answers to questions rather than returning a list of links.

**Answer engine** is an AI platform that generates synthesised, conversational answers to user questions rather than returning a ranked list of links. [ChatGPT](/concepts/platforms/how-chatgpt-search-works), [Perplexity](/concepts/platforms/how-perplexity-ranks-sources), [Gemini](/concepts/platforms/how-gemini-search-works), [Claude](/concepts/platforms/how-claude-search-works), [Grok](/concepts/platforms/how-grok-search-works), and Google's AI surfaces (AI Overviews and AI Mode) are all answer engines. The term distinguishes these platforms from traditional search engines that return ranked link lists.

## Why it matters

The shift from search engines to answer engines is the underlying trend that makes [AEO/GEO](/glossary/geo) necessary as a distinct discipline. When a customer asks an answer engine for product recommendations, the AI synthesizes a response that names specific brands — no clicking through to 10 blue links, no evaluating multiple pages. The answer engine makes the initial brand selection on behalf of the customer. Brands not mentioned in the synthesized answer are excluded from the customer's consideration set.

## How it applies in practice

Cited tracks the major answer engines, each with different behaviour patterns: Perplexity always cites sources explicitly, ChatGPT blends training data with Bing retrieval, Claude relies mostly on training data, Gemini and Google's AI surfaces draw from Google's search index, and Grok integrates X (Twitter) social data alongside web retrieval. Understanding each answer engine's behaviour is key to [AEO/GEO](/glossary/geo) strategy. See [Which AI platforms we track](/methodology/which-llms-we-track) for the full set.

## Related concepts

* [AEO/GEO](/glossary/geo) — the optimization discipline for answer engines
* [SERP](/glossary/serp) — the predecessor concept from traditional search engines
* [Which AI platforms we track](/methodology/which-llms-we-track) — the full set of answer engines Cited monitors