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=== Bit rate ===
The audio [[bit rate]] for a ''Red Book'' audio CD is 1,411,200 [[bits per second]] (1,411 kbit/s) or 176,400 [[bytes per second]]; 2 channels × 44,100 samples per second per channel × 16 bits per sample. Audio data coming in from a CD is contained in sectors, each sector being 2,352 bytes, and with 75 sectors representing 1 second of audio. For comparison, the bit rate of an original speed CD-ROM is 2,048 bytes per sector × 75 sectors per second = 153,600 bytes per second. The remaining 304 bytes in a CD-ROM sector are used for additional data error correction.<!--[[User:Kvng/RTH]]-->
=== Data access from computers ===
Unlike on a [[DVD]] or CD-ROM, there are no "[[computer file|files]]" on a ''Red Book'' audio CD; there is only one continuous stream of [[LPCM]] audio data, and a parallel, smaller set of 8 [[subcode]] data streams. Computer [[operating system]]s, however, may provide access to an audio CD as if it contains files. For example, [[Windows]] represents the CD's Tabletable of Contentscontents as a set of [[Compact Disc Audio track]] (CDA) files, each file containing indexing information, not audio data. By contrast however, [[Finder (software)|Finder]] on [[macOS]] presents the CD's content as an actual set of files, with the [[Audio Interchange File Format|AIFF]]-extension, which can be copied directly, randomly and individually by track as if it were actual files. In reality, macOS performs itsrips ownas as-needed-rips in the background completely, transparent to the user. The copied tracks are fully playable and editable on the user's computer.
In a process called [[ripping]], digital audio extraction software can be used to read CD-DA audio data and store it in files. Common [[audio file format]]s for this purpose include [[WAV]] and AIFF, which simply preface the LPCM data with a short [[header (computing)|header]]; [[FLAC]], [[Apple Lossless|ALAC]], and [[Windows Media Audio Lossless]], which compress the LPCM data in ways that conserve space yet allow it to be restored without any changes; and various [[lossy]], [[perceptual audio coder|perceptual coding]] formats like [[MP3]], [[Advanced Audio Coding|AAC]], and [[Opus (audio format)|Opus]], which modify and compress the audio data to a greater degree in ways that irreversibly change the audio, but that exploit features of human hearing to make the changes difficult to discern.<!--[[User:Kvng/RTH]]-->
== Format variations ==
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