MP3s are digital audio files which are compressed using a standard which is defined by MPEG or the Motion Pictures Experts Group. MPEG was formed for the development of techniques that are used to deal with digital videos. Because most videos have audio, MP3 was developed as an audio extension. MP3 technically stands for “MPEG-1, Layer 3″ and is a lossy compression algorithm which makes use of psycho acoustic modeling that reduces the size of audio files as much as 90 percent.

Psycho acoustics basically takes advantage of certain deficiencies in the human auditory system to get rid of the digital bits which correspond to sounds that humans cannot hear.
For example, humans cannot hear some soft sounds which are in the presence of louder sounds that have a similar frequency such as a conversation being inaudible once a jet plane flies low overhead. Such an effect is referred to as auditory masking. As long as it is done properly, the discarded sounds would not be missed.

MP3s are lossy algorithms in that the original bits could not be recreated or reconstructed from the compressed bits. However, in terms of hearing, an MP3 file is lossless, as the human ear could not really distinguish between a properly encoded MP3 version and a CD recording version. MP3s are able to achieve this transparency at an approximate bit rate of 256 kilobits per second, which is about a sixth of the CD format’s 1.4 megabits per second.

From 1994 through the later years of 1990s, MP3 files started gaining popularity on the Internet. Its popularity rose even more when Winamp and mpg123 were released in the late 1990s. With the launch of the website mp3.com in November of 1997, thousands of songs in MP3 file formats were offered for free. The smaller size of MP3 files allowed for easy file sharing of music and songs which have been ripped from CDs. In 1999, Napster, the pioneer in large peer-to-peer network for file sharing was launched.

However, along with the easy and convenient creating and sharing of MP3s came a widespread copyright infringement. A lot of record companies argued that the free sharing of MP3 files dramatically reduced sales, calling the issue “music piracy”. They started filing lawsuits against Napster, resulting in its shutting down.

Despite the widespread popularity of MP3s, online music retailers choose to make use of the other proprietary formats which have been encrypted or obfuscated, making it more difficult for consumers to use their purchased music files in other ways that have not been specifically authorized by record companies. This attempt to control the use of audio files is called Digital Rights Management.

Today, many individuals choose to use MP3s for their convenience, as they have smaller sizes, allowing them to store more songs on their playlists in their portable MP3 or other music players.