First Paint (FP) is a performance metric that records the time from when a page starts loading to when the browser renders the first pixel on the screen. This metric provides insight into how quickly the browser can begin to display content, even if it's just a background color or a simple layout.

While FP doesn't measure the loading of meaningful content, it is an important indicator of a page's initial responsiveness. Improving FP can be achieved by reducing server response times and optimizing the delivery of critical resources.