Audio files
High-resolution audio
A CD contains 2 channel audio represented by 16 bits samples at a 44.100 Hz sample rate.
If the audio CD contains anything different, it won’t play.
A CD has to be manufactured according to the Redbook standard.
Today recordings are made with 24 bit words and often with a higher sample rate than 44.1 kHz.
On a PC you can play the original recording in the original format.
No need to down-sample the original recording to comply with CD (Redbook) format anymore.
File formats
Using a computer for playback is using audio files as a source.
There are many different file formats.
Something to keep in mind when selecting a media player.
It should be able to support popular formats like FLAC.
The major difference is lossless versus lossy compression.
Formats like MP3 do save an impressive amount of space at the expense of losing finer details. The higher the compression, the more apparent this will be.
The reverse is also true, the higher the bit rate (less compression) the more difficult it will become to distinguish them from the lossless original.
Beside lossless there is lossless compression. This is pretty much like how WinZip works. When expanded you get exactly the same bits as the original non-compressed version.
Although a WAV and a WAV compressed to FLAC and expanded back to WAV are bit identical some claim to hear a difference.