It depends upon whether you burn MP3 files as data or as audio. If you burn them as audio they end up as standard CD audio files which will play on most CD and DVD players. When the audio is converted to MP3 there are some losses, and more losses occur as you convert back to CD audio... but most people don't really notice the difference.

If you burn MP3s as data you can get around ten times as many tracks on a CD, but they need an MP3 capable player.

Okay?! ;o)