Is the disk a hard drive?

No, disk and hard disk are not the same concept. Hard disk is just a type of disk. A magnetic disk is a tape-like device in a computer's external memory. The circular magnetic disk is installed in a square sealed box to prevent scratches on the disk surface, leading to data loss. Disks can be divided into two categories: 1. Hard disks, which are composed of one or more aluminum or glass discs; 2. Floppy disks, whose reading and writing are completed through floppy disk drives.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

Disk and hard disk are not the same concept. Hard disk is just a type of disk.

Disk refers to a memory that uses magnetic recording technology to store data.

Disk is the main storage medium of computer. It can store a large amount of binary data and can maintain data without loss even after power outage. The disk used in early computers was a floppy disk (Floppy Disk, referred to as floppy disk), and the disk commonly used today is a hard disk (Hard disk, referred to as hard disk).

Floppy Disk

Floppy disk is the earliest removable media used in personal computers (PC). Reading and writing floppy disks is done through floppy disk drives. Floppy disk drives are designed to accept removable floppy disks. The commonly used 3.5-inch floppy disk with a capacity of 1.44MB was once very popular. Later, due to the emergence of USB flash drives, the application of floppy disks gradually declined until they were eliminated.

The storage format of a floppy disk: refers to how many concentric tracks each side of the disk is divided into, and how many sectors each track is divided into to store information. Sector is the basic storage unit of a floppy disk. Each read and write to the disk is performed in units of several sectors called "clusters".

Hard disk

The hard disk is one of the most important memories in the computer. Most of the software your computer needs to function properly is stored on your hard drive. Because the storage capacity of hard disk is larger, it is different from memory and optical disk. A hard drive is a hard disk-based storage device used in computers. It stores and retrieves digital data on a flat magnetic surface.

The hard drive consists of one or more aluminum or glass discs. These discs are covered with ferromagnetic material.

Most hard drives are fixed hard drives, which are permanently sealed and fixed in the hard drive. Early hard drive storage media were replaceable, but today's typical hard drives are fixed storage media that are sealed within the hard drive (except for a filter hole to equalize air pressure). With the development, removable hard disks have also appeared, and they are becoming more and more popular, and there are more and more types. The hard disks installed on most microcomputers are called "winchester" technology because they adopt Winchester technology. "Chester hard drive", or simply "warm drive".

Main technical indicators of disk storage

Storage density, storage capacity, access time and data transfer rate.

• Storage density: divided into track density, bit density and area density.

  Track density is the number of tracks per unit length along the radius of the disk, in tracks/inch.

  Bit density is the number of binary code bits that can be recorded per unit length of the track, and the unit is bits/inch.

  Area density is the product of bit density and track density, and the unit is bits/square inch.

• Storage capacity

  The total number of bytes that a disk storage can store.

• Access time

  Access time consists of three types of time: seek time, waiting time, and data transmission time.

• Seek time

  The time required for the disk to locate on the specified track

• Waiting time

  The time after the seek is completed until the information that needs to be accessed on the track reaches under the magnetic head

• Data transmission time

  The time required to transmit data

• Data transfer rate

  The number of bytes of data transferred from disk storage to the host per unit time

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