The principle of hard disk composition

The writing of the data is actually on the platter, the disk can be divided into the sector and the cylinder two units, of which the sector each 512bytes so large.
The first sector of the disk mainly records two important information, respectively:
Primary boot Sector (MBR): Where the boot loader can be installed, 446bytes;
Partition table: Records the status of the entire hard disk partition, 64bytes.
In the 64bytes capacity where the partition table is located, a total of four groups of records are recorded, each of which records the starting and ending cylinder numbers for that section.
Partitions that can be formatted as data access are primarily partitioned and logical partitions, and extended partitions cannot be formatted.
The number of logical partitions varies according to the operating system, in which the IDE's hard disk has up to 59 logical partitions (5th to 63rd), and the SATA hard disk has 11 logical partitions (5th to 15th).

Q: The No. 0 track of the hard disk contains MBR and partition table, please, the smallest unit is the cylinder or the head or track.
For:
The cylindrical surface (Cylinder) is also called a magnetic column.
Add: The smallest unit of software storage is sector sector, the smallest unit of file system is block blocks.
Add: The track in the No. 0 rail of the problem is track, that is, the track.

Disk: A hard disk has two platters, a platter has two sides, is 4 disk surface (each face has a head for reading data). Set to 0-3 plate.
Track: Each disk is divided into N tracks (concentric circles of different radii), the track is composed of sector sector, sector can be imagined as the point of forming a circle.
Cylindrical Surface: 4 tracks with the same radius (with the same track number) on 4 disk surfaces form a cylinder. The 0 cylinder is composed of 4 0 tracks, and 1 cylinders are composed of 4 1 tracks.
Distinguishing tracks: When it comes to 0 tracks, there will be 4, in order to distinguish 4 different 0 tracks on the 0 cylinders, named 0-track [0-3] cylinders respectively. This [0-3] refers to the disk surface, which is not related to the rear cylinder, but the definition is defined. For example, the 0-track 2-cylinder, on the 2nd-plate surface of 0-track.