A hard disk (Hard Disk Drive) is a magnetic, physical storage medium in computer technology that stores the operating system, applications and files in a non-volatile manner.
This data is written to the surface of rotating disks. These work together so that data can be stored, read and deleted on the hard disk. Saving is done by remanence (remaining magnetization) and reading of information is done by non-contact scanning of the magnetization of the disk surface.
Hard disks enable the storage of large files and quick access to the stored data. They are therefore an important element of many IT systems for efficient data storage and management.