CD Audio and iTunes

The CD Audio format was the world’s first widely used entry in the digital audio format life cycle. The creation of this format was the start of the CD revolution. Instead of vinyl albums, which were a pain to deal with and included lots of hisses, pops, and other distractions when played, listeners began enjoying digital music. In addition to being much easier to handle than LPs, CDs provided a much better listening experience and were—and are—much more durable than records.
They also sounded much better than cassettes and could be just as portable.
Eventually, CD Audio made its way to computers, which now can provide all the music-listening enjoyment of a home stereo plus much more, thanks to applications such as iTunes.
Although you can use iTunes to listen to your audio CDs, typically you will just convert those CDs into one of the newer digital formats and store that content on your computer’s hard disk so you don’t have to use a CD when you want to listen to music. You will also make use of this format when you put your iTunes music on your own audio CD so that you can play your iTunes music when you are away from your computer.