The density of data held on an area of the a recording medium’s surface. This is one of the parameters that manufacturers of disk drives and tape recorders constantly strive to increase. For example one currently-available high-capacity drive from Seagate achieves around 1Tb/square inch. When compared to the 130 Gb figure reported here in the 2008 edition of this book, this shows not only the continuing high rate of development of disk-drive technology, but also that seven years is too long between editions of the Digital Fact Book! With development continuing apace, yet greater capacities can be expected in future editions.
See also: Hard disk drives