APC, which stands for Alternative PHP Cache, is a framework used for caching the compiled source code of a given script application, which could speed up a database-driven website several times. Each time a PHP web page is opened, the script pulls the website content that needs to be shown from a database, parses and compiles the program code, and then the result is shown to the website visitor. While this is necessary for sites with regularly changing content, it is a total waste of processing time and system resources for a site which doesn't change, like an informational portal that shows the same content at all times. When the webpages for such a site are compiled, APC caches them and delivers them any time a user accesses them. Since this saves the time to request content from the database and to parse and compile the program code, your Internet site will load much quicker. APC is really effective especially for scripts with larger source code.