WordPress is a powerful web publishing system, but it can’t do everything (yet). Fortunately WordPress was designed to be extended by plugins — modular programs that add functionality to your site. Once you learn how to use WordPress plugins, you can do just about anything with your website.
There are a huge number of plugins available that add new features to WordPress.
There are plugins to block spam, publish podcasts, and speed up your WordPress site. If you have some specific need that isn’t accommodated by WordPress out of the box, chances are there’s a plugin to meet your needs.
This video shows you how to find, install, and use WordPress plugins.