This tab will likely become your main destination for configuring the resources used by your websites. Here, you can set up FTP accounts and databases, back up your sites, view statistics, use the file manager, and even see a site preview if DNS is not pointed to your server yet. For that matter, you can register domain names or order SSL certificates from this page as well. Needless to say, there will be quite a lot to cover on this tab later on.
Next: Mail Tab