Raid is a solution to protect data when a hard drive is broken (usually in a server on a NAS). The data is then stored on at least two disks. With, for example, DRBD you can also realize this by creating a “raid” between two machines over the network.
But then my data is safe anyway? With an extra disk/discs Do I still protect my data when a disk goes bust?
Yes, that’s true. But a backup protects against much more than just a broken drive.
A backup should also protect you when a file has been deleted or damaged, by RANDSOM-ware is infected (depending on the way of creating/saving the backup) or…. ….. …. (there are many more things to think about).
In summary, RAID (if properly equipped) only helps with a defective disk, not other things that can corrupt data.