The latest rage in 'net audio continues to be MPEG Audio Layer 3 stream technology (MP3 for short). This is the latest official MPEG standard to be released from the ISO/IEC standardization body (MPEG4 is in the works) and is by far the most powerful member of the family. MPEG Audio Layer 3 utilizes a combination of extremely complex methods to attain high compression ratios while preserving CD-quality audio.
While it might not sound overwhelmingly impressive at first glance, when you take into account that without compression it takes approximately 175 Kilobytes to store just one second of CD-quality stereo sound, the full benefits of MP3 and the older MPEG standards quickly become apparent.