A click is counted whenever someone selects a result on a search engine results page and lands on the destination site. It's the most direct measure of search performance there is: an impression means a result was shown, but a click means someone actually chose it over everything else on the page.
Google Search Console reports click counts per page and per query, which makes it possible to see not just how a page ranks but whether that ranking is actually converting into visits. A page that ranks well but gets few clicks relative to its position often has a title or meta description that isn't compelling enough to win the choice, even though the ranking itself is fine. Click-through rate, clicks divided by impressions, is usually the more useful number to track over time, since raw click counts rise and fall with search volume for reasons that have nothing to do with the page itself.
