How does the "AutoDelete" option work?

[JimmiG]

I've set up a couple of jobs using the Powershell script from here https://www.veeam.com/blog/veeam-backup ... shell.html
It's working fine, but I'm a bit unsure how the AutoDelete option works, and especially when and how the deletion of old backups is triggered.
Is there some background process on the system Veeam is installed on, that keeps checking and deleting in the background, or is it done the next time the script is executed, or something else? Surely there must be some process that does this, because files cannot "auto destruct" on their own.

Suppose, for example, that I made a backup with the "-AutoDelete In1Week" option, and I decide I need to keep this particular backup for longer. How can I prevent Veeam from deleting it?

[foggy]

Retention applies at the end of the successful job run. You cannot mark the particular backup so it has longer retention, retention applies to the entire backup chain.