Plugins change the default behavior of the WordPress software that you can download from WordPress.org.
Plugins reside in the plugins directory inside the wp-content directory of your WordPress installation.
To install a new plugin for WordPress all you have to do is FTP the plugin’s folder to the plugins directory.
Download and unpack the plugin from the WordPress Plugin Directory, then upload to your site. Pay attention to the Installation tab on the plugin’s page in the WP directory. Some plugins need a few extra steps to be completed, but most follow the standard installation.
You may be directed to the plugin’s homepage for further instructions on how to install that particular plugin.
Also, you’ll need to activate the plugin before it will function. Go to the plugins tab from the WP Dashboard, find your new plugin in the list of inactive plugins, and click on Activate.
You’re all set! Your new plugin may have a management page, so check the Manage Tab of the WP Dashboard for a new link for managing your new plugin.