WordPress is one of the most popular blogging platform out there at this time. It is very simple to make your own blogging website on WordPress.
There are lots of plugins and theme out there which can help you to make your blog more user friendly, if you too had installed plugins or theme on your WordPress then you might see update notification as publisher release updates for them, WordPress too release update for it too.
Automatic Updater is a nice WordPress plugin which automatically update your blog. As soon as any update will be available it will update push update for it. It will update your WordPress core, plugins and themes too.
Once update is done, it will send a email to you in which it states what update it has done. While this will be useful for the vast majority of sites, please exercise caution, particularly if you have any custom themes or plugins running on your site.
You should also be aware that this will only work on WordPress installs that have the appropriate file permissions to update through the web interface it will not work if you usually FTP updates to your server.