Core Web Vitals are three measurements Google uses to grade how a page feels to a real visitor: how fast the main content appears, how quickly the page responds to a tap, and how steady the layout stays while it loads. Google treats them as ranking signals, so they affect both experience and search position.
The one most people feel is speed, measured by Largest Contentful Paint, the moment the main content shows up. Google’s bar for that is under 2.5 seconds on a phone. This matters for a small business because people leave slow pages, so a site that fails a vital is found less and abandoned more. About half of sites miss at least one of these marks on a phone (Web Almanac, 2025).
You can check your own vitals in Lighthouse, the free tool built into Chrome. I build sites to pass them on a real phone, not just a fast laptop, because being readable does not help if the page makes a visitor wait. Speed is part of being found, covered in The Art of Being Found.