In a nutshell
Core Web Vitals are the three metrics Google uses to grade real page experience. LCP (Largest Contentful Paint) is when the biggest visible element finishes rendering — loading speed, good at 2.5s or less. CLS (Cumulative Layout Shift) scores how much content unexpectedly jumps as the page loads — visual stability, good at 0.1 or less. INP (Interaction to Next Paint) is the delay from a tap or click to the next frame drawn — responsiveness, good at 200ms or less. A page passes only when all three are good.
