This article deals with the principles and technologies of mass storage in thin films. This includes optical recording, magnetic recording and magneto‐optical recording. Sometimes we follow the historical development and discuss alternative concepts, eg, magneto‐optical versus phase‐change recording as rewrite principle or the competition between HD‐DVD and BD as an optical system for blue recording.
For optical recording, we try to give a more comprehensive overview that also includes the main aspects of production technology and how this in intertwined with optical principles, materials science and industrial standards.