To do this, one loads Cloud station on the NAS and Cloud station client on the Mac. The latter can be configured in such a way that the desired data is continuously backed up on the NAS without having to do anything else during operation.
RAID is possible with all NAS systems from Synology & QNAP (I don't know much about the rest, but they should also work) with at least two internal hard disks (2 bay and more). With 2 bay systems, this is simply mirrored (RAID 1) & from 4 bay, RAID 5 or other is then also possible. RAID 0 is not recommended, as this offers no redundancy from 2 bay. For more information on RAID --> ask Google.