Zero-click describes a search after which the user doesn't click any result. The reason can be a direct answer in the SERP, a new query, an error or simply giving up.
What is zero-click?
Google can show the weather, an exchange rate or opening hours directly. Featured snippets and AI Overviews extend direct answers to more complex informational queries too.
A search without a click doesn't always mean a satisfied user. Read external studies carefully, and keep in mind that their measurement methods differ.
What it does to traffic
For some informational queries, CTR can drop even when the ranking stays the same. The impact depends on whether the summary fully covers the need or the user still wants detail, proof or a transaction.
In GSC, track clicks, impressions, CTR and query type over time. You can't pin a change on the AI summary without checking the actual SERP and other factors.
How to respond
Create content with value of its own: data, a comparison, a tool, a demo, a product or an expert service. The user needs a reason to go from the short answer to your site.
At the same time, build an accurate brand and content that's easy to cite. A mention without a click can build awareness. Measure its business value separately and don't overstate what it shows.