Core Web Vitals
Core Web Vitals are Google's set of user-experience metrics measuring loading, interactivity, and visual stability: Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift. They are measured from real-user field data and used as part of the page experience signals.
Why It Matters
They are a confirmed ranking factor and, more importantly, correlate with real user satisfaction. Poor scores raise bounce and abandonment, so improving them can lift both rankings and conversion at the same time.
Common Mistake
Optimizing only lab scores in tools like Lighthouse while ignoring field data from the Chrome User Experience Report. Rankings use real-user data, so a green lab score on fast hardware can hide slow experiences for actual visitors.