To use a plugin, a WordPress site owner simply needs to download and install the plugin from the WordPress plugin directory or from another marketplace. Once installed, the plugin will add its functionality to the site, either by modifying the site's appearance or by adding new features to the site's backend. Some plugins require configuration or customization, while others work right out of the box.
WordPress plugins are written in PHP, the same programming language used to build WordPress itself. Plugins can add custom code to a WordPress site, hook into existing functionality, or modify existing functionality. For example, a plugin could add a new custom post type to a site, modify the appearance of a site's navigation menu, or integrate with an external service like Google Analytics.
