APC, which is an acronym for Alternative PHP Cache, is a framework used for caching the compiled source code of a given script application, that could speed up a database-driven website several times. When a PHP webpage is accessed, the script pulls the site content which should be shown from a database, parses and compiles the program code, and then the result is displayed to the visitor. While this is necessary for sites with routinely changing content, it is a waste of processing time and system resources for a website which doesn't change, such as an informational portal which shows identical content at all times. As soon as the webpages for such a site are compiled, APC caches them and delivers them every time a website visitor accesses them. Since this saves the time to request content from the database and to parse and compile the code, your website will load significantly quicker. APC is very efficient particularly for scripts with larger source code.