Core Web Vitals
Core Web Vitals are three metrics defined by Google for the user experience of a web page – load time (Largest Contentful Paint), visual stability (Cumulative Layout Shift) and interaction responsiveness (Interaction to Next Paint) – which, in Google's words, match what its core ranking systems reward.
In practice
Good values come above all from optimised image sizes, lean code, reserved space for images and ads, and fast hosting. Google Search Console and PageSpeed Insights show the values per page and provide concrete suggestions for improvement.