APC, which is short for Alternative PHP Cache, is a framework used for caching the compiled source code of a script application, that can speed up a database-driven Internet site several times. Any time a PHP page is opened, the script pulls the site content which needs to be shown from a database, parses and compiles the code, and then the result is shown to the website visitor. While this is necessary for sites with routinely changing content, it is a waste of processing time and system resources for a site that does not change, such as an informational portal that displays the exact same content all the time. When the pages for such a site are compiled, APC caches them and delivers them whenever a visitor accesses them. Since this saves the time to collect content from the database and to parse and compile the code, the site will load considerably quicker. APC is really effective particularly for scripts with massive source code.