To back up the websites related to correctly selected subscription, Go to Account > Back Up Websites.

Then click Back Up to create a new backup.

There are two types of backups

01.Full backup 

02.Incremental backup

A “Full” backup includes all data you specified.

Using incremental backups significantly reduces the duration of a backup operation, CPU load, and the disk space occupied by backup files, and, therefore, improves the backup performance.

Plesk includes the following data in incremental backups:

1. Web hosting data changed since the time of the last backup (full and incremental).
2. Mail data changed since the time of the last backup (full and incremental).
3. Full backup of database data.

Note that incremental backups contain whole files created on a subscription, not their parts. Plesk determines whether the data has been changed based on whole files. For this purpose, Plesk uses an index file that is created for each backup at the time of backup creation. The index file lists all files that existed in a subscription, and information about them, such as size, modification date, permissions or owner. A full backup lists all files, while an incremental one may list just a few files that have changed.