Core Web Vitals are Google's metrics for user experience. They affect SEO ranking.
LCP (Largest Contentful Paint): Time until largest content element renders. Target: under seconds.
FID (First Input Delay): Time from first interaction to response. Target: under ms.
CLS (Cumulative Layout Shift): Visual stability. Target: under .
INP (Interaction to Next Paint): Responsiveness throughout session. Replacing FID.
Interview tip: Know these metrics and their targets. Your interviewer expects you to reference them when discussing performance.