And yes, they can ship hard drives with the full data in case of a need for full data recovery.
Ozzy, RAID is a system of stringing multiple hard drives together to get extra storage and/or redundancy (so if a hard drive fails you're OK). There are different configurations of RAID (called levels); each RAID level has a different scheme for distributing the main data and redundant data. Most of these can tolerate a single hard drive failure, and keep the system up and running without data loss or downtime. That allows for replacing that failed drive and having the system rebuild the information that was on the old (failed) drive onto the new one. RAID 6 will even tolerate two drives failing. So if you're running a mission-critical system, such as processing thousands of financial transactions every second, then you need RAID to provide the assurance that your system won't crash with the loss of a hard drive. For local audio storage, however, RAID is likely overkill unless your data exceeds that of the size of drives currently available (typically around 4-6TB), in which case you could take advantage of RAID to spread all that data across multiple drives seamlessly. The audio storage local backup solution can be easily managed by built-in tools like Time Machine (Macintosh). Then you'll need a cloud-based backup on top of that to handle such situations like a house fire, weather catastrophe, or theft.
Hope that helps.
Michael