Windows Server 2019 Administration Fundamentals - Second Edition

Understanding optical disk drives

Unlike HDDs, which use an electromagnetic field to read and write data to/from disk platters, optical disk drives (ODDs), as shown in Figure 9.14, utilize laser beams with a specific wavelength to read and write data to/from compact discs (CDs). Always try to differentiate between the ODDs and optical discs (ODs), such as CDs or DVDs. The former is the device where the CD or DVD is inserted. CDs contain tracks in the form of a spiral. The starting point for storing data on CDs is the inner track. As is the case with HDDs, optical discs are measured by capacity in bytes. Usually, the capacity of common CDs is between 650 MB and 700 MB, while common DVDs range from 4.7 GB to 8.5 GB. In contrast to HDDs, the ...