WP Super Cache is a plugin for WordPress that generates static HTML pages from your dynamic WordPress blog. Once static pages are generated, those pages are displayed to visitors, using less server resources than dynamic webpages.
For busy websites running WordPress, HostGator recommends that a caching plugin, such as WP Super Cache be enabled. This will allow your website to handle more simultaneous visitors and also typically loads much faster than without the caching plugin.
WordPress Super Cache will be installed by default with all new QuickInstall and Fantastico WordPress installations. If you or a client wants it to be removed, that user can simply deactivate it in their wp-admin/ directory.
For more information on how to set up WP Super Cache, please read: