Noun
pregroove (plural pregrooves)
A premolded spiral groove in an optical disc, used to guide the laser beam when the disc is read or written.
As well as providing timing information, the ATIP (absolute time in pregroove) is also a data track containing information about the CD-R manufacturer, the dye used and media information (disc length and so on). Source: Internet
Photomicrograph of the groove in a CD-R disc The polycarbonate disc contains a spiral groove, called the "pregroove" (because it is molded in before data are written to the disc), to guide the laser beam upon writing and reading information. Source: Internet
The polycarbonate disc is coated on the pregroove side with a very thin layer of organic dye. Source: Internet
The pregroove is not destroyed when the data are written to the CD-R, a point which some copy protection schemes use to distinguish copies from an original CD. Source: Internet