Advanced page cache module is a useful server-side module, it's used to cache pages to reduce server side loading time, generally this module could increase server side loading time for 5+ times.
Advanced page cache module is a useful server-side module to save dynamic web pages to static HTML pages and send the static html pages to users, by doing so to greatly improve server-side speed. The more modules you've installed, the more time will be saved. Why you need to use this cache...