14. The WordPress Toolkit: Plug-Ins
WordPress Modular Architecture
WordPress is a modular web content management platform, meaning that when you install WordPress on a web server, you get a basic set of built-in (or “core”) functionality that all other WordPress users get, even users of the WordPress.com hosted software. Where the modular part comes in is that WordPress allows anyone to extend the software to do just about anything. A plug-in usually isn’t a standalone program; it needs WordPress to do basic tasks, hence the name. Plug-in support is included only with versions of WordPress software (meaning WordPress.org), as the powers that be at WordPress.com don’t allow users to install plug-ins themselves.
Thousands of WordPress plug-ins ...