To degauss is to demagnetize. The term is named after Carl Friedrich Gauss, a German mathematician who applied mathematics to the study of geo-magnetism. A gauss is a unit of magnetic flux density equal to 1 maxwell per square centimeter.
Degaussing is a popular technique for destroying data on magnetic storage tapes. By changing the magnetic field on the tape with a box-like device known as a degausser, the data on the tape can effectively be destroyed. This allows reuse of tapes that don't have prewritten tracks. Degaussing can also be used to erase the contents of a hard drive, USB thumb drive, smart phone or floppy disk.Degaussing is commonly used to improve the picture resolution on electronic displays. Many display manufacturers include an internal coil that will degauss the display when it is turned on. Display monitors and televisions with cathode ray tube (CRT) technology are particularly subject to the buildup of magnetic fields.