There's a whole industry built around the MP3 data-compression format, but did you know that by using MP3s to burn music CDs, you lose part of the original recording as the data compressor does its work?
Such "lossy" compression schemes result in conveniently small data file sizes, but like audio cassette tapes of old, fidelity is lost each time you convert MP3s back and forth, to and from the CD-burnable .WAV file format, resulting in digitally degraded music files that become increasingly removed from the CD-quality benchmark to which listeners aspire.
The industry that relentlessly flogs MP3 probably doesn't want you to know that it is possible to obtain truly "lossless" audio compression with very little trouble.