The three Core Web Vitals are LCP (Largest Contentful Paint, ≤2.5s), INP (Interaction to Next Paint, ≤200ms), and CLS (Cumulative Layout Shift, ≤0.1). INP replaced FID in March 2024.
Good scores measurably affect rankings on commercial pages. More importantly they measure real user-perceived speed and stability.
Measure with field data — CrUX in PageSpeed Insights, or the Web Vitals JS library on your own site. Lab data (Lighthouse) is for diagnosis, not for monitoring.