Plugins extend and expand the functionality of WordPress. Once a plugin is installed, you may activate it or deactivate it here.
You can find additional plugins for your site by using the new Plugin Browser/Installer functionality, Or by browsing the WordPress Plugin Directory directly and installing manually.
To manually install a plugin you generally just need to upload the plugin file into your /var/www/historic-wordpress/2.7/wp-content/plugins
directory.
Once a plugin has been installed, you may activate it here.