Which term best describes the storage mechanism that utilizes rotating disks?

The term "disk storage" accurately describes systems that use rotating disks as their primary mechanism for data storage. This typically refers to traditional hard disk drives (HDDs), where data is stored magnetically on physical disks that spin at high speeds. The read/write heads move across these disks to access or save data, allowing for large storage capacities at relatively low costs.

In contrast, solid-state drives (SSDs) use flash memory and have no moving parts, making them significantly faster and more reliable than traditional disk storage. A hybrid drive combines both SSD and HDD technologies but doesn't solely represent storage utilizing rotating disks. External storage encompasses various forms of data storage that are not integrated into a computer's internal architecture, such as USB drives or external HDDs, which may also use rotating disks but does not exclusively define this storage mechanism.

Thus, "disk storage" is the most precise term for the technology based on rotating disks.