Varnish cache is a web application accelerator also known as a caching HTTP reverse proxy. It can accelerate your website by the factor 300 - 1000. Varnish caches all resources (websites, images, styles, scripts, etc.). Varnish cannot cache the website if it has set a cookie, but the images, styles and scripts of this webpage are served by varnish without a problem.Some Cookies (e.g. Wordpress Cookies) are removed by the server for better caching.