AI Overviews is a feature of Google Search, made by Google. For some queries the results page shows an AI-generated snapshot of key information about the topic, with links to web pages for further reading. It uses generative AI, models that write new text from given material.
Google's systems decide for each query whether an overview adds value beyond the classic results, so it often does not appear. To build a response, AI Overviews may use a query fan-out technique: it issues several related searches across subtopics and data sources, then shows a set of supporting links. People can ask with text, voice or an image. Google warns that AI responses may include mistakes. For site owners there is no special markup or file: a page that is indexed and eligible for a snippet in Google Search can be shown as a supporting link, clicks are counted in the Search Console Performance report, and the nosnippet, data-nosnippet, max-snippet and noindex controls limit what is shown.
AI Overviews is part of Google Search, not a separate product, so it has no plan or price of its own.