MP3, MPEG Layer 3 Audio (.mp3)
The MP3 Audio file format
A MPEG-1 or MPEG-2 Audio Layer III files (file extension name: MP3) is the standard audio storage file type. Most music players (and smart phones) play music using MP3 files. The lossy compression reduces the quality without straying tremendously from the original, uncompressed recording. This is done by removing those sounds the human ear is incapable of hearing and processing. MP3 files are great for portability since tracks with the CD quality are taken to the smaller MP3 file. Thus, after compression, more files can fit on a single disk than the original release, decreasing upload and download time of audio files regardless of connection speed.
Technical details of MP3 files
Using lossy data compression, audio files are compressed for easy storage and sending. It was preceded by the MPEG-1 file type but continued into a new category (MPEG-2 Audio Layer III). Unlike MPEG-1 files an MP3 file stores audio information only. Any images associated with the audio (as seen on iPods and smart phones) need to be stored in a different file. MP3 files are reduced to 128kbit/s at a ratio of 11:1 from the original recording. Accuracy of the sounds is decreased in such that the changes are in the areas outside the perception of most human ears (audio masking), leaving the important information, and resulting a much smaller file size. There are ways to reduce the file size even further but it decreases the audio quality to a much higher degree.