Both? You can hook it up to your mac or PC and it can charge your phone/ipod or sync things from iTunes. If you have the wall box thing thing, you can plug it into that and it will charge from that wall your device from the wall. I also when feeling lazy plug mine up to my PS3 and charge my iPhone 4s and it charges from there too (though not as fast). I have the other one in white and it works fine.