In general, creating any backup starts with uploading a full copy of your data to the storage which serves as a reference point for subsequent incremental backups. However, it is unreasonable to create and upload a full copy of every file each time when you need to apply any changes made to your locally stored data to the backup stored in the cloud. This is why you need to consider utilizing other kinds of backup.
The way in which a full backup processes your data depends on the kind of data that you back up:
- When creating an image-based backup, a full backup uploads a complete copy of your data to a target storage (and creates a new backup version) each time the backup plan is being executed.
- When creating a file-level backup, the backup service re-uploads an entire file only if it has been changed since the last backup date (as with an incremental backup, a file is not re-uploaded if its modification date is earlier than the last backup date).