APC, or Alternative PHP Cache, is a PHP module that caches the output code of database-driven script apps. Dynamic PHP websites store their content in a database that is accessed whenever a visitor loads a webpage. The content which should be viewed is gathered and the code is parsed and compiled before it is delivered to the website visitor. All of these actions take some processing time and require reading and writing on the web server for each and every page that is loaded. While this can't be avoided for Internet sites with regularly changing content material, there are various sites that feature the exact same content on a lot of of their pages all the time - blogs, info portals, hotel and restaurant sites, etc. APC is extremely useful for this type of Internet sites since it caches the previously compiled code and shows it each time visitors browse the cached webpages, so the code doesn't have to be parsed and compiled repeatedly. Not only will this lower the server load, but it'll also boost the speed of any website several times.