A disk is a flat, round, portable object made of metal, plastic, or paper that is used for storing information. Disks are read by machines called drives. The first disks were used in computers in the 1950s. Today, people use disks to store music, videos, and computer programs.
Most disks are made of metal or plastic. The information on a disk is stored on a thin layer of metal or plastic called the surface. The surface is divided into tiny areas called tracks. Each track is divided into even smaller areas called sectors.
The read/write head of a disk drive floats very close to the surface of the disk. When the disk is spinning, the head moves from track to track, reading or writing information.
The speed of a disk drive is measured in rotations per minute (RPM). The faster the disk spins, the faster the drive can read or write information.
There are two types of disks: hard disks and floppy disks. Hard disks are rigid disks covered with a hard material. They are used in computers to store large amounts of information. Floppy disks are flexible disks covered with a soft material. They are used to store small amounts of information.
Applications of hard disk drives include personal computers, workstations, servers, and mainframes. The primary characteristics of an HDD are its capacity and performance. Capacity is specified in unit prefixes corresponding to powers of 1000: a 1-terabyte (TB) drive has a capacity of 1,000 gigabytes (GB; where 1 gigabyte = 1 billion bytes). Performance is specified by the time required to move the heads to a track or cylinder (average access time) plus the time it takes for the desired sector to rotate under the head (average latency, which is a function of
As was stated in the introduction, disk is a very important part of magnetic media. Disk drives are used in computers to store and recall information from a variety of different types of media. This is because disk drives are able to store large amounts of data in a very small space. Additionally, disk drives are very fast and reliable, which makes them ideal for use in computers.