This page serves as a handy reminder of your PrestaShop configuration: version, server info, PHP version, MySQL version. All these prove really useful when you need to report an issue to the PrestaShop developers, or simply your webmaster or web host.
There is one last section, titled "List of changed files". Right after you have first installed PrestaShop, the only thing that this section displays is "No change has been detected in your files".
But after you've installed some modules and a couple of themes, made advanced changes to some override classes or deleted files altogether, this list will show the difference between your current installation of PrestaShop and what it used to look like in its pristine state. This helps you see what changes have been made to your installation... and therefore what to take into account if you want to update your store manually, or if you are moving files to a new server.