Glossary about Compact Disc


Appendable Disc
An open multisession disc. A readable disc that can have additional data (sessions) written to it.

A binary digit, either zero or one.

A byte is made up of 8 bits. It represents one character of information. A kilobyte (K) is approximately 1000 bytes. A megabyte is approximately 1,000,000 bytes.

A portion of memory that is reserved to hold data temporarily before it is transferred to the CD recorder.


This stands for Compact Disc Digital Audio. A CD-DA disc conforms to the Red Book standard.

This stands for Compact Disc Recordable. These discs are writable with a CD writer drive and either a PC or Macintosh computer.

This stands for Compact Disc Read Only Memory. A CD-ROM conforms to the Yellow Book standard. The data stored on it can be either in the form of audio, computer or video files.

CD-ROM Mode 1 & 2
The Yellow Book specifies two types of tracks, Mode 1 and Mode 2. Mode 1 is used for computer data and text and has an extra error correction layer. Mode 2 is for audio and video data and has no extra correction layer. CD-ROM/XA An expansion of the CD-ROM Mode 2 format that allows both computer and audio/video to be mixed in the same track.

Closed Disc
Also called "non-appendable". Once a disc is closed no further data can be added to the disc.

Close Session
This prevents further data from being added to the disc. This also stores file and directory information to the Table of Contents.


Factual information such as sound, images, text, and numbers in a form that can be processed by a computer.

Disc at Once
A CD-ROM disc that the data is written in a single session and the Table of Contents is written before the data.

Hierarchical File System - used by the Macintosh system for storing files.

Generally a CD-ROM that contains both ISO 9600 and Macintosh (HFS) files.

ISO 9600
The international standard for CD-ROM file format.

Joliet is an extension of the ISO 9660 standard, developed by Microsoft for Windows 95 and Windows NT, to allow CDs to be recorded using long filenames. It also allows for using the Unicode international character set. For files recorded to CD, Joliet allows using filenames up to 64 characters in length, including spaces. Joliet also records the associated DOS-standard name for each file so that the disc may be read on DOS systems or earlier versions of Windows. [As in Windows 95/98, file and folder names up to 256 characters long, which may include spaces, are allowed. To maintain DOS compatibility, a DOS-standard (8+3) filename is associated with each file; these names are created automatically by Windows 95/98 and can be viewed in Properties for each file. To create these DOS-standard names, long filenames are truncated and the tilde (~) is added; a number may also be added to distinguish between files].

A CD that contains tracks of differing formats. Most often this term refers to discs that contain both computer data (Yellow Book) and audio (Red Book) tracks. The data is on the first track and the audio is on the following tracks.

A way of writing to a CD that allows more data to be added to readable discs at a later time.

A format for storing CD quality audio. This format is a heavily compressed audio signal with a 10:1 ratio of compression, while retaining its CD quality.


Open Disc
A CD that can accept additional tracks or sessions. SCSI This stands for Small Computer System Interface. A SCSI controller can support up to seven (7) devices(hard drives, CD recorders and scanners). Each SCSI device in a chain must have a unique ID number. Sector The information stored on a CD is in sectors or blocks; each sector contains 2,048 bytes (Mode 1) or 2336 bytes (Mode 2).

A fully readable complete recording that contains one or more tracks of computer data or audio on a CD.

Simulate Write
A program that allows your CD writer to simulate the writing to a disc with-out actually writing data. This is used to test the hardware and file structure for errors.
Terminator A SCSI device that is required at the end of a SCSI chain. TOC This stands for Table of Contents. On a CD disc it is used by the computer or CD player to locate the information on the CD.

Super VCD
Super Video CD (SVCD) is an enhancement to Video CD that was developed by a Chinese government-backed committee of manufacturers and researchers. The final SVCD spec was announced in September 1998, winning out over C-Cube's China Video CD (CVD) and HQ-VCD. In terms of video and audio quality, SVCD is in between Video CD and DVD, using a 2x CD drive to support 2.2 Mbps VBR MPEG-2 video (at 480x480 (NSTC) or 480x576 (PAL) resolution) and 2-channel MPEG-2 Layer II audio.

A particular amount of data written on a CD. The size of a track can vary from a few kilobytes to the whole contents of the CD.

Track at Once
A technique of writing to a CD disc where individual tracks are written separately and the Table of Contents is written after the data. The disc is not readable until "closed" (i.e. Table of Contents is written).


Video CD
Similar to an audio CD, a Video CD disc has a capacity of about 70 minutes of video. It contains several tracks. The first track is a standard ISO 9660 data track containing files which tell the VideoCD player how to locate and play the other tracks on the disc. It may also store still pictures, playlists, and menus. The menus allow the user to select from various tracks or "scenes" to play. Playlists can present the various tracks in different orders. The other tracks on the disc are one or more audio/video tracks, which may be followed by one or more standard CD-DA audio tracks. The audio/video tracks use MPEG-1 compression which compresses the video by a factor of approx. 60 to one.

VCD resolution is 352x288 for PAL and 352x240 for NTSC. When playing PAL VCDs, most NTSC DVD players and Video CD players, such as the Panasonic and RCA players, deal with the difference is to chop off the extra lines. The Sony NTSC players scale all 288 lines to fit. Because PAL VCDs are encoded for 25 fps playback of 24 fps film, there is usually a 4% speedup. Playing time is shorter, and the audio is shifted up in pitch unless it was digitally processed before encoding to shift the pitch back to normal.



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