====== Glossary of Terms ======

===== Ablation =====

  - **Optical Ablation**. A permanent recording mechanism used in early [[extras:glossary#worm|WORM]] optical disk systems, where data is written by physically removing or altering the recording layer of the media.

===== CAV =====

  - **Constant Angular Velocity**. A sector arrangement format in which data sectors are positioned at fixed angular intervals around a disk, maintaining a constant rotational speed. Sectors typically have lower linear data density on tracks farther from the center.
  * //See also:// [[https://web.archive.org/web/20250126030035/https://telcontar.net/Misc/maths/CAVvsCLV.php|Telcontar — CAV vs CLV capacity]]

===== CLV =====

  - **Constant Linear Velocity**. A sector arrangement format in which the disk's rotational speed varies with the read/write head's position to maintain a constant linear velocity. Data is typically recorded at a consistent linear density, maintaining approximately the same bit spacing along the track.
  * //See also:// [[https://web.archive.org/web/20250126030035/https://telcontar.net/Misc/maths/CAVvsCLV.php|Telcontar — CAV vs CLV capacity]]

===== Disc =====

  - A (usually) flat, circular recording medium whose data-bearing surface is exposed and not permanently enclosed within a protective housing.

===== Disk =====

  - A recording medium where the data-bearing disc is completely enclosed — either permanently or removably — within a protective cartridge, casing, sleeve, or hard shell.

===== Disc-Based Enclosed Media (DBEM) =====

  - Any of a number of data storage formats that consist of an optical disc enclosed in a protective cartridge.

===== OMDR =====

  - **Optical Memory Disk Recorder**. A professional class of high-capacity, magneto- optical recording systems and media used for digital data archiving, medical imaging, and broadcast video mastering.

===== WORM =====

  - **Write-Once, Read-Many**. A class of optical storage media where data can be written only a single time to a specific sector. Once recorded, the data becomes permanent, immutable, and cannot be overwritten, modified, or deleted.
  * //See also:// [[extras:glossary#ablation|Ablation]]