First, it acts as a stereo headset so you can listen to music and second, it acts as a handsfree earpiece so you can make and receive phone calls. Plus it also acts as a remote, so you can control your MP3 player wirelessly, too. I use the player to listen to music as well as my books from Audible.com . If you are listening to music for long periods, you will want to ensure that the headphones are comfortable and don’t make your ears hurt! Again, you will probably need to pay a higher price for a headset that feels good and light on your head than one that feels like it’s got you in a headlock!