(A) Track
(B) Geometrical sector
(C) Track sector
(D) Cluster
A disk drive track is a circular path on the surface of a disk or diskette on which information is magnetically recorded and from which recorded information is read.
A track is a physical division of data in a disk drive, as used in the Cylinder-Head-Record (CCHHR) addressing mode of a CKD disk. The concept is concentric, through the physical platters, being a data circle per each cylinder of the whole disk drive. In other words, the number of tracks on a single surface in the drive exactly equals the number of cylinders of the drive.
Tracks are subdivided into blocks (or sectors, pages) (see: Storage block and Virtual page).
The term track is sometimes prefaced with the word logical (i.e. "3390-9 has 3 logical tracks per physical track") to emphasize that it is used as an abstract concept, not a track in the physical sense.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction