All storage devices, from hard disks to solid state drives to SD cards, must be partitioned to become usable. A device must have at least one partition, although you can create several partitions on any device.

Partitioning divides a disk drive into one or more reserved areas called partitions. Information about these partitions are stored in the partition table on the disk drive. The OS treats each partition as a separate disk that can contain a file system.

You create more partitions to simplify backups, enhance system security, and meet other needs, such as setting up development sandboxes and test areas. You can add partitions to store data that frequently changes, such as user home directories, databases, and log file directories.