WordPress offers a large number of plugins to add functionality to your site. They range from anti-spam comment filters to helping you build a small-scale social network.
How you manage and use the plugin depends on its developer. You can view all of the currently installed plugins by clicking Plugins on the menu.
Some WordPress plugins can slow your site's performance. Deactivating plugins and then testing your site's performance again can help you troubleshoot speed issues. For more information, see Troubleshooting WordPress.