PRPL is a web architecture devised by Google to enhance the performance of websites and apps on devices with inconsistent network connections, and it stands for Push, Render, Pre-cache, and Lazy-load. It involves pushing critical resources using techniques like <link preload> and HTTP/2, rendering the initial route, pre-caching other routes, and lazy-loading additional routes as needed. Although HTTP/2 Server Push is still emerging and not widely supported, Gatsby, a framework that adheres to the PRPL pattern, optimizes site performance by rendering a static HTML version initially, pre-caching linked resources, and dynamically creating pages on the client when users navigate. This approach ensures high performance, as elaborated in Gatsby's development discussions, and reflects the broader emphasis on web performance strategies.