Human: What is the difference between a cd player and a mp3 player? Assistant: 
The main difference between a CD player and an MP3 player is that CDs contain digital audio data, while MP3s are compressed digital audio files. A CD player will play back music in its original format, while an MP3 player can store and play back audio files in various formats including MP3, WAV, AIFF, and OGG. Additionally, CD players generally have higher sound quality than MP3 players.