APC, which is short for Alternative PHP Cache, is a framework used for caching the compiled source code of a given script app, which can boost a database-driven Internet site several times. Each time a PHP web page is opened, the script pulls the content which has to be displayed from a database, parses and compiles the program code, then the result is displayed to the website visitor. While this is necessary for websites with routinely changing content, it's a total waste of processing time and system resources for an Internet site which doesn't change, like an informational portal that displays the same content at all times. As soon as the webpages for such a site are compiled, APC caches them and delivers them each time a user loads them. Since this saves the time to request content from the database and to parse and compile the code, your Internet site will load much quicker. APC is really effective in particular for scripts with larger source code.