WordPress Plugin can be thought as add-ons of Mozilla Firefox. It means WordPress do the main function of CMS and plugin provide the additional functionality. Wordpress plugin are small software that you can upload on your site to enhance or extend some functionality. Wordpress plugin provide powerful features to the self-hosted version of WordPress site. The WordPress plugins world has now greatly developed. Whatever additional thing you want to do in your site there will be a surely a plugin available for this in the WordPress plugin directory in most of the cases. WordPress plugin directory has thousands of plugins for your WordPress powered site.