Parity-based RAID protection uses fewer physical drives than mirroring to provide the same level of data protection. It does this by using error correction codes to detect and correct errors in the data. This allows for a much more efficient use of storage capacity, as it only requires the same amount of storage capacity as the actual data, rather than requiring twice the storage capacity as with mirroring. Additionally, parity RAID systems have the advantage of being able to recover from drive failures without having to wait for the data to be rewritten to the remaining drives, as is the case with mirroring.