In a rotating-disk computer, a sector of data that is stored at an angle on the disk which is physically angled, either clockwise or counter-clockwise.
A dynamic disk has faster access time than a standard or fixed disk and so it’s good for applications with high throughput needs like multimedia applications or database servers where more input/outputs per unit of time are needed. A rotating-disk consists of a rigid circular plate with an encoding molded into its surface usually in concentric circles around the circumference called “data sectors”. Data sectors contain information encoded as magnetic flux changes that represent binary units known as bits. A spinning plate can store 12 linear rows of data per side if there are 9 tracks in each row, for a total of 144 sectors. If any one sector contains data that needs to be saved, then it can’t be overwritten by another data unit either from a program or hardware failure. This is why a certain section of the disk known as a “bad block” cannot be written on until a replacement comes in. There are different ways to replace these bad data sectors. One of which is to create a mapping table with a list of bad sector locations and their corresponding good sector number. This method requires a lot of disk space as a file has to be kept for every bad block location on the disk.