Core Web Vitals are Google's measures of real-user page experience: how fast the main content loads (LCP), how quickly the page responds to input (INP) and how much the layout shifts while loading (CLS).
They're measured from real Chrome users' visits and shown in Search Console and PageSpeed Insights.
Common fixes are smaller images, less JavaScript, fast hosting and reserving space for images and ads so content doesn't jump.
Why it matters for a launch
A fast page keeps more launch visitors and is a small ranking factor. Slow pages lose people before they read your headline.