Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A recording head is the physical interface between a recording apparatus and a moving recording medium. Recording heads are generally classified according to the physical principle that allows them to impress their data upon their medium. A recording head is often mechanically paired with a playback head, which, though proximal to, is often discrete from the record head.Note that Magneto-optical recording, though using optics and heat, should properly be considered a magnetic process, since the data stored on magneto-optical media is stored magnetically.