MP3 is the most popular music format on the Internet and is a way of compressing music from CDs without losing quality.  It enables a pirate to download a typical song in minutes and then play it on their computer without paying a royalty to the artist or record company.  MP3 stands for MPEG (Moving Picture Experts Group) 1, Audio Layer 3, and is similar to the compression used to send satellite TV signals.  A typical song on a CD my be 10 megabytes per minute or around 25 megabytes for the whole song in size, but when it’s compressed using MP3, an entire song is reduced to 3-5 MB.  “MP3 measures compression settings in terms of a file's bit rate--the average number of bits required for one second of sound. To obtain near CD-quality audio, MP3 requires a bit rate in the range of 128 to 192 kilobits per second.  This size makes it perfect to transfer on the Internet, and a flourishing underground trade in MP3s has started.  You can even fit hundreds of songs on a CD with MP3 format.  There are numerous Internet sites where MP3 files can be found and traded, but the clear leader is Napster.  In fact, Napster has made it so easy to trade songs that many artists have filed lawsuits against them and certain universities for allowing the use of Napster on their campuses.
    Music is compressed into the MP3 format using a ripper program.  This program takes music, in digital or analog format from a CD, record, tape, or other source, and compresses it using the MP3 specification.  This results in a much smaller file that sounds almost identical to the original.