What is a hard disk?

Andrey Kim
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What is a hard disk?

Hard Disk (HDD - Hard Disk Drive) is an electronic storage medium based on the principle of magnetic recording. In most computers, it is the hard disk that is the main data storage device. In this article we will discuss in more detail what a hard disk is and what its name means.

Why is a hard disk called hard?

Information stored on a hard disk is recorded on hard plates - magnetic disks made of aluminum or glass and coated with a layer of ferromagnetic material or silica. That is why a hard disk is called a hard disk, as opposed to a floppy disk's flexible electronic magnetic recording medium.

Hard drive is also often referred to as a hard drive. When developing a hard disk, engineers called it briefly 30-30, which meant using two modules of 30 MB each.

Hard disk - how does it work?

The principle of the hard disk is in many ways similar to the work of a tape recorder. The working surface of the disk moves relative to the read head.When an electric current is applied to the head, it excites an alternating magnetic field, which in turn affects the ferromagnet with which the disk is covered, which changes the direction of the magnetization vector of the macroscopic region in the magnetic crystal, and this change depends on the field strength.

Other types of electronic media

In addition to hard drives today there are other types of electronic media - floppy disks, disks and semiconductor media (flash drives). Floppy disks have almost become obsolete since they can store very little information, CDs and DVDs are also not very popular, they are mainly used to distribute programs, games, music, etc., but flash drives are now used everywhere.

Internal and portable drives

Hard drives are both internal and portable. Internal are in the system unit of each computer, and portable are used as a very voluminous flash drive. Portable removable drives can be of any size, from a few gigabytes to terabytes.