RAID 1, or Redundant Array of Independent Disks Level 1, is a data storage technique that mirrors data across two or more hard drives. This means that every piece of information is duplicated, providing a backup in case one drive fails. If one drive becomes unusable, the system can continue to operate using the other drive(s) without data loss. The primary benefit of RAID 1 is increased data reliability and protection. However, it does not improve performance significantly, as writing data to multiple drives can slow down the process. Users often choose RAID 1 for critical data storage where redundancy is essential, such as in servers or personal computers.