The Many Types of Optical Disc

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Virtual CD supports all of the most common types of CD. These are generally divided into audio (usually music) CDs and data CDs. Some CDs contain both audio tracks and data tracks.


The following are the most common formats for data CDs:

CD-ROM – Normal CDs; you have probably used these with your computer many times.
DVD – Successor to the CD-ROM, with considerably greater storage capacity. DVDs store all information as data. This applies for audio and video DVDs. DVDs often have mixed content, such as a video for viewing and a data section for use on a computer.
HD-DVD – Like Blu-ray, this is a successor to the DVD. The HD-DVD format is already becoming rare, because Blu-ray has captured a much bigger market share.
Blu-ray – Successor to the DVD. This format is used primarily for high-definition movies. On occasion, it is also used for storing large amounts of data.
Video CD – Video CDs were the electronic medium used for movies before DVDs were released on the market. The video quality is nowhere near as good as that offered by video DVDs.
Super Video CD – This CD type offers better video quality than a normal video CD. Lower compression improves the visual quality, but also increases the space required, so that only about 20 minutes of video fit on each CD.
Photo CD – Photo CDs are used to store digital photographs; for example, for viewing on a television. Many film developers today offer the option of having photos stored on a CD.


The most common formats for audio CDs are:

Audio CD – Normal music CD, for use with the CD player in your stereo system.
CD-Text – These are audio CDs with additional information about the album, artist and songs on the CD. The additional information can be read only by devices that have CD-Text capability. In other devices (such as your stereo's CD player) they run just like normal audio CDs.


Mixed formats, containing both audio and data tracks:

CD-Extra – These CDs have an audio segment and a data segment. When inserted in a CD player, the audio tracks are played just like on a normal audio CD. When inserted in the CD drive on a computer, the data segment is executed.
Mixed Mode CDs – These CDs have a data track and several audio tracks. In the past, this type of CD was widely used for computer games. Today they are rarely used.


In addition to tracks, another unit of data organization used on some CDs is the "session." A multi-session CD is created in a series of steps, and each session is in turn divided into tracks. This type of CD format is used, for example, to create CDs with both data and audio tracks. One example of this is the CD-Extra format, which contains the audio segment in the first session and the data segment in the second. When the CD is placed in a computer, the program(s) in the data segment (usually animation) are executed. When the same CD is placed in a CD player, the data sector is ignored and the CD is treated as a normal music CD.


In addition to these normal CD types, there are a few kinds of CD (such as game or audio CDs) that use non-standard formats. These CDs have properties that are not found in the industry standards that define how CDs are to be made. For example, a data CD that contain unreadable sectors does not conform to the standards for data CDs.



Virtual CD can usually read out non-standard CD formats. It may be necessary, however, to configure additional settings (such as "Read CD geometry") to make a virtual CD from a non-standard source CD.