Back in the early days of the iPod (not all that long ago), music files were often transferred over the Internet. Internet speeds were slower then and storage capacities on mp3 players and iPods were not that great. So there was a real need to compress music files to speed up downloads and minimize storage requirements. The most popular compression format developed in that era was .mp3, which remains in wide use today.
Formats like mp3 are called “lossy” formats. This is because when music files are compressed using a “lossy” format, compression is accomplished by throwing information away. This makes for a very compact file, but some of the information contained in the original file is lost and can never again be recovered. It could easily be said that since the earliest days of audio, the mp3 format represented the first “innovation” that actually served to decrease the quality of sound reproduction. Even though it offers low levels of sound quality, mp3 remains the most popular format in use today.
If you are building a music streaming system today, it would seem that maintaining the highest quality level should be among your top priorities. In this regard, you could conceivably store all of your music files uncompressed. While the lack of compression would mean your files would be maintained at the highest possible quality level, the failure to compress would dramatically increase the disk space required for your library. Fortunately, there are solutions that maintain quality and decrease storage requirements at the same time.
As stated above, the .mp3 compression algorithm achieves its results by throwing information away and, once it is gone, it can no longer be recovered. As such, it is called “lossy” compression. But there also exists a number of “loss-less” compression algorithms that allow you to decrease the size of the music file and completely recover a perfect bit-for-bit copy of the original file when decompressed. Examples of this include the very popular .flac format and Apple’s .aiff format. Both of these substantially decrease the size of music files, and yet provide uncompressed files on playback that are identical to the original in every way.
CD ripping programs normally offer at least one of these loss-less compression options, allowing you to substantially decrease your music library’s storage requirements. It is a win-win situation. Audio player applications generally don’t care which format you use. They can handle them all. They note the form of compression used based on the file extension of the music file and decompress it accordingly. The result is a bit-for-bit copy of the original. So you can feel secure in knowing that your can compress your music files without exacting a performance penalty.