An inline citation is the clickable source link an AI answer places next to a specific claim, letting the reader verify it and passing referral traffic to the cited page. You see them in Google's AI Overviews, ChatGPT with search, Perplexity, and Gemini — usually as a numbered marker or a small source chip.
In an answer-first world, an inline citation is often the only visibility a brand gets — the user reads the synthesised answer, and the citation is the doorway back to your site. Being the cited source also confers a trust signal: the AI is effectively vouching that your page backs up the statement. Lose the citation and you lose both the click and the implied endorsement.
Citations tend to go to pages that state a fact cleanly and are easy to extract. A page that answers "how long does concrete take to cure?" with a direct sentence — "Concrete reaches about 70% of its strength in 7 days and full strength in 28 days" — is far more citable than one that buries the figure under three paragraphs of preamble.
Engineering pages to be quoted this way is the core of answer engine optimization, and it works hand in hand with earning placement in AI Overviews.