Google has been testing highlighting content on web pages based on clicking on a features snippet from the Google search results for years now, and was tested on both desktop and mobile.
But now, this is now live and works on most Google featured snippets, as well as most web browsers.
According to Danny Sullivan from Google, he said that this feature went live last week after all the years being tested. He said “we’ve done this regularly with AMP pages since December 2018. We tested with HTML pages last year, as noted. We now do it regularly HTML pages, since last week.”
By doing a search on Google on either mobile or desktop, and you see a featured snippet, click on it. After that, Google might anchor you down and/or highlight the text on that web page on that web page that you saw in the snippet.
After you click on it, Google will highlight the text on the web page that was displayed in the snippet in the search results:
Danny Sullivan linked to this help document that says “clicking a featured snippet takes the user directly to the featured snippet text on the source web page. This happens automatically. There’s no markup needed by webmasters to enable a featured snippet. If a browser doesn’t support the underlying technology needed, or if our systems can’t confidently determine exactly where within a page to direct a click, clicking a featured snippet will take a user to the top of the source web page.”