RAID1 Mirrors the data across multiple disks (Minimum of 2). By spreading the data across more than one disk should you suffer a fault (Drive failure) your drive controller would simply send you an alert that a drive has failed and that you should replace the failed drive at your earliest convenience. There are speed benefits compared to a single drive however you loose the capacity of the mirrored drive.
RAID1 Mirrors the data across multiple disks (Minimum of 2). By spreading the data across more than one disk should you suffer a fault (Drive failure) your drive controller would simply send you an alert that a drive has failed and that you should replace the failed drive at your earliest convenience. There are speed benefits compared to a single drive however you loose the capacity of the mirrored drive.
For example – two 10tb hard drives in RAID1 will only give you the capacity of 10tb as the second drive would be used for backup of the first.
Simply put – Mirroring gives you a mirror of the drive at the expense of capacity.