There are also car DVDs with a monitor or display, CD is just a player.
CD disc capacity is generally about 700M, while the DVD capacity of at least 4.7G or more.
If it is to enjoy music or CD is better, the general car is the majority of CD.
DVD discs can burn music; CD is the main format of music, is more pure than DVD, which is why music enthusiasts like to use CD to listen to music for the reason.
