Varnish is a website accelerator platform, which caches content for the sake of faster response times. It’s sometimes referred to as an HTTP reverse proxy as well and it interacts between a web server and a web browser. When a website visitor opens a given page, the content is requested by the web browser, and then the web server handles this request and sends back the required info. If Varnish is enabled for a certain site, it will cache its pages on the first request and if the user opens a cached page for a second time, the data will be delivered by the caching platform and not by the server. The boosted speed is an end result of the substantially faster response speed that the Varnish platform offers compared to any server software. Of course, this does not mean that the visitors will continue being served the same content again and again, as any modification on any of the web pages is reflected in the content that the Varnish platform caches in its memory.