Video thumbnails are a feature on search engine results pages (SERP) that appears for certain search queries. The thumbnails appear when the search engine determines that the web user might be interested in seeing a video clip, for instance if they search for the results of a sports fixture.
Video thumbnails may display results directly from YouTube, especially if the browser used is Google Search. Clicking on these thumbnails directly opens YouTube at the right video. For webpages that have embedded their own video clips, the webpage (upon which the video is embedded) will be opened when the user clicks on the thumbnail.
