[amingilani]

You’re conflating offsite backups, a type of backup, with the class of backups. Backups can be on-site. Is it as durable? No. Is it a backup? Yes.

[charcircuit]

I'm paying homage to the saying that "RAID is not a backup." In a technical sense RAID can create a backup of each block, but that is not what people are referring to when they say that phrase. They mean it as a backup as one may need for disaster recovery.