The process of getting a web application production-ready after a restart / reinitialization. In essence, the application gets hit with requests in order to cache critical data before it starts handling production traffic. Each time your application restarts, for reasons including but not limited to new code deployment or scaling up, response to the first requests on the frontend may be delayed as pages are being compiled and cached. The Sitefinity Warmup service
rules out those delays and makes sure your site is configured for optimal performance. The Warmup service calls all sitemap pages, compiles them based on sitemap priority and stores them in the output cache, so they are ready to be served to visitors.