While you can perform a full backup on your website, cPanel does not allow restorations using the full backup file.
Once you have downloaded the compressed full-backup file, you will need to decompress it and then restore individual portions of your website using the files contained in the full-backup file package.
However, in addition to your website files, etc. the full backup file will also contain server files. If you are new to restoration or if you are unsure which files to use to restore your website, we strongly recommend you follow the instructions outlined in Restoring Website with a Partial Backup File.