Memory storage density

The recording density, also called data density, or data recording density is a measure of the number of data per unit of area or unit of length, which can be stored on a disk. When magnetic tapes is a unit of measurement usually BPI (bits per inch bits per inch = ) or FCI ( Flux Changes per Inch = flux change per inch ) used for hard disks bits per square inch.

Particularly in connection with discs, but also magnetic tapes, the terms Simple density, double density, four times density, high density and enhanced density or the English counterparts are single density (SD), Double Density (DD), Quadruple Density (QD ), high density (HD) and Extended density (ED ) is used. This is the ratio of the recording density to standard density.

The recording density depends on magnetic media, among others, depend on what material the storage medium is coated. The higher the recording density is, the greater is the storage capacity.