What are Core Web Vitals?

Core Web Vitals are the three metrics Google uses to measure how your pages actually feel to a real visitor - and they feed into search ranking, so they are worth knowing by name:

• Largest Contentful Paint (LCP) - how long until the biggest thing on screen (usually the hero image or headline) has loaded. Measures perceived load speed.
• Cumulative Layout Shift (CLS) - how much the page jumps around as it loads. Measures visual stability.
• Interaction to Next Paint (INP) - how quickly the page responds when someone taps or clicks. Measures responsiveness.
• They are scored on real visitors - Google grades each at the 75th percentile of your actual traffic, not a one-off lab test.

You can see your own scores free in Google PageSpeed Insights. Fix the worst-scoring of the three first - that is where you will feel the difference and where Google does too.