The book type is a field of four bits at the start of every DVD (in the physical format information section of the control data block) that indicates what the physical format of the disc is.
DVD (an abbreviation of "digital video disc" or "digital versatile disc") is a digital optical disc storage format invented and developed by Philips and Sony in 1995.
DVD recordable and DVD rewritable refer to part of optical disc recording technologies.
The DVD+RW Alliance is a group of electronic hardware, optical storage and software manufacturers who in 1997 created and promoted a format standard of recordable and rewritable DVDs, known as the "plus" format.
DVD-R DL (DL stands for Dual Layer), also called DVD-R9, is a derivative of the DVD-R format standard. DVD-R DL discs hold 8.5 GB by utilizing two recordable dye layers, each capable of storing a little less than the 4.7 gigabyte (GB) of a single layer disc, almost doubling the total disc capacity. Discs can be read in many DVD devices (older units are less compatible) and can only be written using DVD-R DL compatible recorders. It is part of optical disc recording technologies for digital recording to optical disc. DVD-R DL has compatibility issues with legacy DVD-ROM drives known as pickup head overrun. To avoid this issue, the two layers of the disc need to be equally recorded. But this is a contradiction with the sequential nature of the DVD recording. Thus DVD Forum under Pioneer's lead developed a technology known as Layer Jump Recording (LJR), which incrementally record smaller sections of each layer to maintain compatibility with DVD-ROM drives. DVD-R DL media has been discontinued by most manufacturers. DVD+R DL is dominating the market for dual layered media.
The gigabyte is a multiple of the unit byte for digital information.
MiniDVD (also Mini DVD or miniDVD) is a DVD disc which is in diameter.
MultiLevel Recording (ML) (also known as M-ary) was a technology originally developed by Optex Corporation and promoted by Calimetrics to increase the storage capacity of optical discs.
Opposite Track Path (OTP) is a technique used in optical technology, which when correctly implemented allows faster (though not un-noticeable) switching from layer 0 to layer 1.
Koninklijke Philips N.V. (Philips, stylized as PHILIPS) is a Dutch multinational technology company headquartered in Amsterdam currently focused in the area of healthcare.
commonly referred to as Pioneer, is a Japanese multinational corporation based in Tokyo, Japan that specializes in digital entertainment products.
SuperDrive is a trademark used by Apple Inc. for two different storage drives: from 1988 to 1999 to refer to a high-density floppy disk drive capable of reading all major 3.5″ disk formats; and from 2001 onwards to refer to a CD/DVD reader/writer.