APC, which means Alternative PHP Cache, is a framework used for caching the compiled source code of a given script application, that can boost a database-driven website several times. Any time a PHP page is accessed, the script pulls the website content which needs to be displayed from a database, parses and compiles the code, then the result is displayed to the website visitor. While this is necessary for websites with constantly changing content, it's a total waste of processing time and resources for an Internet site that doesn't change, like an informational portal that shows the very same content all the time. When the pages for such an Internet site are compiled, APC caches them and delivers them each time a website visitor opens them. As this saves the time to get content from the database and to parse and compile the program code, your Internet site will load much faster. APC is very efficient particularly for scripts with massive source code.