The Core Web Vitals are a set of new metrics introduced by Google to measure the performance of web applications. These metrics include First Contentful Paint (FCP), Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), and First Input Delay (FID). Each metric measures a different aspect of how a web application responds, such as when content is first rendered, when the largest amount of content is drawn on the screen, and when the user can interact with the page. To use these metrics, developers need to collect performance data from real users and interpret it in context. The Core Web Vitals are not yet standardized but are expected to become a ranking indicator starting in 2021. Developers can gather field performance data using tools like Chrome DevTools and then send the data to a server using the Beacon API for further analysis. Understanding the data requires distilling hundreds or thousands of points into meaningful insights, taking into account factors such as user experience, network conditions, and device capabilities.