APC, which is short for Alternative PHP Cache, is a framework used for caching the compiled source code of a script application, which can boost a database-driven Internet site several times. When a PHP webpage is accessed, the script pulls the content that has 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 Internet sites with regularly changing content, it's a waste of processing time and system resources for a website that does not change, for example an informational portal which displays the exact same content all the time. When the pages for such an Internet site are compiled, APC caches them and delivers them each time a visitor loads them. Since this saves the time to request content from the database and to parse and compile the code, the Internet site will load considerably quicker. APC is very helpful particularly for scripts with large source code.