How does a hard drive store data?

A traditional hard disk drive stores information magnetically on one or more rapidly spinning platters coated with a magnetic material. Data is recorded as a pattern of tiny magnetised regions, each representing a binary digit, either a 1 or a 0. A tiny device called the read-write head, mounted on an arm that sweeps across the disk, changes the magnetic orientation of these regions to write data and senses their orientation to read it back. The platters spin thousands of times per minute, and the head floats just nanometres above the surface without touching it. Because information is stored magnetically, it remains even when the power is off. Newer solid-state drives have no moving parts and instead store data in flash memory chips, making them faster, quieter, and more durable, though the principle of storing binary data remains the same.