RAID stands for Redundant Array of Independent Disks, used for data protection and performance improvement.Main types of RAID are hardware RAID (controller) and software RAID (OS managed).Popular RAID levels include RAID 0 (striping for performance), RAID 1 (mirroring for redundancy), RAID 5 (striping with parity), RAID 6 (striping with double parity), RAID 10 (mirror + stripe), and RAID 01 (stripe + mirror).Use cases vary for each RAID level, from gaming PCs to critical storage systems.