Backup:
Backups allow you to download a zipped copy of your entire site or specific parts of your site, such as your home directory, databases, email forwarder configuration, or your email filters configuration. The server does not automatically schedule these backups. If you wish to use scheduled backups, contact your service provider.
Full Backup:
A full backup creates an archive of all of your website’s files and configuration. You can use this file to move your account to another server or to keep a local copy of your files.
You can select a full website backup or "Partial Backups" allow you to take backup of a particular data.