Hi
@Reva
Is your site a WordPress site? If so, one possibility is that your hosting provider mass enabled the plugin across the server that your site is hosted on. You should have seen a notice at the top of your wp-admin describing the situation. If this is not the case, please let us know.
As for what this plugin does, it caches your site's pages so that they can be served to your clients faster. The plugin will detect any changes that you make to your posts, so that the content is never out of date in most cases.
Let us know if you have any more questions or concerns, and we'll be happy to answer them!
Cheers,
Kevin
