Due to the expansion of the amount of data and documents [i.e., text, line diagrams, images, digital video, animation, sound files, three‐dimensional (3‐D) virtual reality “walkthroughs,” computer aided design (CAD), and product lifecycle management (PLM) 3‐D interactive model files, measured data from machines and processes, and others) we create, store, and archive, digital mass storage technology is rapidly growing. Until the arrival of compact disc read–only (CD‐ROM) technology, the magnetic tape and then the hard disk, which was capable of reading as well as of writing data using magnetic media, were the most obvious mass data storage solutions, as they still are today for many applications.
As is the case with many new technologies, cost, robustness, security, and reliability of storing and retrieving data are of utmost interest to every direct or indirect computer user; therefore, CD‐ROMs and digital variety discs (DVD‐ROMs) have been developed as a relatively low cost (i.e., byte per cent) optical alternative for magnetic mass data storage and retrieval.
Obviously during this development, the magnetic storage industry was (and still is) fighting back, by simultaneously lowering its prices on mass storage devices as well as by increasing data transfer rates and reliability. Simultaneously, the compact disc industry researched and developed an alternative to CD‐ROM technology, which is often referred to as DVD, or DVD‐ROM, which is capable of storing several times that of the CD‐ROM capacity (the actual details will be discussed here).
Data read/write/access speeds have changed too, in that initially the CD‐ROM drive, in comparison with the magnetic hard disk drive was very slow, capable of transferring approximately 150 Kb/sc (as often referred to as the 1 × or single‐speed CD drive), whereas CD‐ROM drives achieve 56 ×, and even faster read data transfer rates, meaning approximately 8400 Kbs/sc. This rate is close to a “good” hard disk drive's read/write speed. (Obviously when analyzing the transfer rate issue, the interface and the entire computer hardware and software system integration quality is important too.)
To summarize this introduction, mass storage devices and the storage media employed are increasingly important; thus, technologies such as optical CD‐ROMs and DVDs are thriving. Other alternatives, most importantly the emerging and increasingly fast(er) intranets and the Internet, in the long run will offer more acceptable data transfer rates and bandwidth than what we have at the time of this writing. These alternatives could take off some of the burden of the individual computer user, office, or multimedia studio of storing and archiving digital data and documents—obviously at a price, security, and reliability that will ensure the future and viability of the CD‐ROM and DVD (high‐definction DVD; see below) technologies.
