Largest Contentful Paint (LCP) is a web performance metric that measures the time it takes for the largest visible content element on a webpage to load. This element can be an image, video, or block of text, and it is crucial for user experience. A fast LCP indicates that the main content is loading quickly, which can lead to higher user satisfaction. LCP is part of Core Web Vitals, a set of metrics developed by Google to assess the quality of user experience on websites. A good LCP score is typically under 2.5 seconds, while anything above 4 seconds is considered poor. Optimizing LCP can improve a site's performance and search engine ranking.