Each time a Vault Services backup job runs, it follows these steps providing protection to new or modified file:
1. The job begins to build a list of all the files that meet the backup job requirements (including those files that have already been protected).
2. The job starts to work through the list. It may start working through the list before the entire list has been generated, so there is a possibility you will see the total list size grow even while the job is transferring.
3. For each file the job finds in the list, it will check to see if the file is already protected. If it is, the job simply moves to the next file. This means that only new or modified files will be backed up. This is what makes the process incremental.
4. If the file is not already protected, the job will proceed to encrypt, verify, and transfer.