APC, which is short for Alternative PHP Cache, is a framework used for caching the compiled source code of a script application, which could boost a database-driven website several times. Every time a PHP web page is accessed, the script pulls the site content which has 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 Internet sites with frequently changing content, it's a waste of processing time and system resources for an Internet site which does not change, for example an informational portal which displays the exact same content all the time. As soon as the webpages for such a website are compiled, APC caches them and delivers them any time a user opens them. Since this saves the time to collect content from the database and to parse and compile the code, the Internet site will load significantly faster. APC is very helpful particularly for scripts with larger source code.