How Hard Disks Stored Data?
The hard disks memories store information on one more circular platters (or disks) which are continually spinning. These rotating disks are coated with a magnetic material and stacked with space between them. Information is recorded on the surface of rotating disks by magnetic heads as tiny magnetic spots . These heads are mounted on access arms. Information is recorded in bands. Each band of information on a given disk is called a track.
A hard disk is really a set of stacked “disks,” each of which, like phonograph records, has data recorded electromagnetically in concentric circles or “tracks” on the disk. A “head” (something like a phonograph arm but in a relatively fixed position) records (writes) or reads the information on the tracks. Two heads, one on each side of a disk, read or write the data as the disk spins. Each read or write operation requires that data be located, which is an operation called a “seek.” Concentric circles on the magnetized surface of the magnetic disk are known as Tracks.
The tracks are commonly divided into pie-shaped sections called sectors. In most systems, the minimum quantity of the information which can be transferred is a sector. The subdivision of one disk surface into tracks and sectors.
The tracks on the disk surface are divided into invisible segments known as Sectors.
A motor rotates the disk at a rapid speed. Data are recorded on the tracks of a spinning disk surface and read from the surface by one or more read/write heads.
The hard disks of today have storage capacity measured in Tera bytes(TB), most common being 1TB to 4TB.