MP3, short for "Moving Picture Experts Group Audio Layer III," is a type of digital audio format often used to store and transfer sound recordings for playback. Many digital musical players, such as the iPod, are specially formatted to play MP3 audio files. The technology, first developed in 1991 and widely used beginning in the late 1990s, has a number of advantages and a few disadvantages over other digital player formats.
Through the use of digital music compression, MP3 players are able to carry an enormous number of songs. While a single CD for a CD player can carry less than 80 minutes of music, an MP3 player can carry thousands of minutes of music. This means owners of MP3 players don't have to carry their cumbersome collection of CDs with them, making MP3 players excellent for travel.
MP3 players are generally quite small and light, with some, such as the iPod Nano, weighing less than 56.7gr and being less than a cubic inch in size. By contrast, even the lightest portable CD player generally weighs at least half a pound and is at least as large as the CD it is playing.
Ease of Dissemination
Because of the MP3 format, digital music is available widely on the web. While CDs must be physically shipped, digital music can be quickly downloaded off the Internet. This allows the MP3 player owner access to a far wider selection of music as well as the ability to sample tracks easily before purchasing them.
Poorer sound quality
Generally, the sound quality of the MP3 format is not as good as that of the CD, meaning that CD players provide clearer audio than do MP3 players. Although MP3s can be compressed at a higher bit rate, most are encoded at 128 kilobits per second, compared with CDs, on which the listener receives sound at 196 kilobits per second, about 50 per cent higher.
CDs can be scratched, causing them to skip. MP3s are generally skip-free. However, if an MP3 is encoded with a skip, it will always play back that way and, unlike a CD, cannot be cleaned.
No MP3 Resale
Unlike CDs, albums on MP3s cannot be resold. When people purchase a song from iTunes or another online MP3 store, they are not so much buying the song as indefinitely leasing it. This may limit the ability of owners of MP3 players to refresh their libraries frequently, as, unlike owners of CD players, they cannot legally trade their songs for new ones.
MP3 players are generally more expensive than CD players. However, CD albums, at £9 to £13, are generally more expensive than MP3 albums, which cost only about £6.