AAC - "Advanced Audio Coding", next generation audio codec developed by Fraunhofer that seeks to preserve audio quality at lower bitrates. High licensing costs have kept this audio codec from the mainstream. Apple iPods can play this codec.
Album Art - A digital image showing the physical cover originally shipped with the album.
Bitrate - The amount of data used in a given period of time to represent sound waves. This value will generally take the form of kilobits per second (kbps). A bitrate of 128 kilobits per second uses 128,000 bits (amount of computer memory) to store each second of audio. MP3 encoded at 192kbps is generally considered equivalent to uncompressed CD-audio by the average human ear.
Burning - Term for writing data to a CD or DVD. Backups of Digital Music Libraries can be archived to DVD however it is now more common to store the files on an external hard drive.
CD Recordable (CDR) - A compact disc onto which data or audio can be written once. Audio CDs can be recorded and played in car, home, and other standard CD players.
Cloud Computing - A service offered online to deliver software and storage solutions as required rather than have these stored on your own computer or server.
Codec - Short for "compression/decompression" generally consisting of some mathematical algorithm used to both compress and store the CD audio, as well as playback to the compressed audio files.
Constant Bit Rate (CBR) - Bitrate remains the same throughout the duration of the audio file, regardless of the actual audio data being compressed. Compare with variable bit rate (VBR).
Decoding - Generally refers to the process occurring behind the scenes by an audio player (such as an iPod), allowing the digital file to be converted into sound you can hear.
Encoding -The process of converting an uncompressed format (such as CD Audio) to one of several compressed digital formats.
Free Lossless Audio Codec (FLAC) - A codec developed by the open-source community which is freely available for use. The lossless files produced by this codec are identical in quality to the original CD Audio.
ID3 Tag -A small chunk of information stored at the beginning of an mp3 file that can store metadata (artist, album, track, etc - see Metadata).
Kilobytes Per Second (Kbps) - A unit of measurement generally used when discussing bitrate. A 128kbps file contains 128,000 bits of data for every second of content being stored. Uncompressed formats use approximately 1411 kbps, while a compressed format generally uses only 128-192kbps.
Metadata - Information about a particular CD, generally consisting of artist, album, and track information. Album information usually includes the year the album was released, its genre (jazz, rock, etc), and possibly album art.
MP3 - MPEG Layer III, by far the most commonly used, compressed digital audio format. Very high compression is achieved by eliminating sounds that the human ear can't hear or doesn't easily pickup. The compression process results in files that can easily be transmitted over the Internet, written to CD/DVD, or stored on portable devices such as the Apple iPod. A properly encoded MP3 will be indistinguishable from the original CD to most individuals.
Normalization -A process which adjusts a number of audio files such that they seem to play at approximately the same volume.
Ripping - Also called digital audio extraction, this is the process of taking CD audio and recording it to a computer in an uncompressed file format (wav). When the transfer is from CD to MP3, the process consists of both ripping and encoding.
Variable Bit Rate (VBR) - Option allowing the encoder to allocate more space to more complex portions of the audio track, and less space to simpler portions (e.g. silence). A track encoded at 128kbps VBR may use only 64kbps to represent the leading silence into a song, but 320kbps for the subsequent guitar solo. Generally, VBR allows for a higher quality file using roughly the same file.
WAV - An uncompressed audio file generally used on PCs. CDs must first be extracted to wav files before they can be compressed to another format (see MP3, WMA, etc).
Windows Media Audio (WMA) - Microsoft's proprietary audio codec designed to compete with MP3. Claims competitive sound quality at lower bitrates.