Citation (AI citation)
When an AI system attributes or links to your content in its answer; the AI equivalent of a search result position.
Definition
A citation in the AI context is when an AI system (ChatGPT, Perplexity, Claude, Google AI Overviews, etc.) uses your content to answer a question and attributes it — by naming your site, including a link, or both. It is the GEO analogue of ranking in traditional search: your content is surfaced in the answer. Citations can be explicit (named source, clickable link) or implicit (content shapes the answer without attribution). Monitoring citations measures your GEO effectiveness.
Grounding vs displayed citations
In generative search systems (AI Overviews, AI Mode, ChatGPT Search), the model first relies on a set of grounding URLs (sources retrieved upstream). Only a subset of these is then displayed to the user as clickable links. Studies that do not separate “URLs used for grounding” from “URLs actually shown” can over- or underestimate a domain’s visibility. In practice, one can distinguish: sidebar-visible sources, in-text citations (links in the response body), and hidden grounding URLs (consulted by the model but not shown). For a technical analysis of Google AI Overviews and AI Mode, see AIO/AIM Deep-dive (RESONEO).
Relevance to GEO
The goal of GEO is to increase the likelihood and quality of citations. Strong structured data, E-E-A-T signals, backlinks, and agent-friendly content improve the chance your site is cited when users ask relevant questions.