RAID (Redundant Arrays of Independent Disks) combines multiple disks to improve performance or provide redundancy, managed either through hardware or software. This courselet focuses on Software RAID, guiding users through creating and managing a RAID 5 array using mdadm on Ubuntu, highlighting its single disk fault tolerance, enhanced read performance, and efficient storage, but slower random write operations. It concludes with steps to create and mount a filesystem on the array, verifying data availability despite simulated device failure, growing and shrinking the array, and then safely dismantling the RAID setup, ensuring users understand the full lifecycle of RAID array management.