A surface USB charger is a cable that goes from the device's Universal Serial Bus, or USB, port to the computer's port. Personal handheld electronic devices can use a USB charger to recharge their batteries on a computer or for data transfer between the two connected devices.
For the device plugged into a USB port to go into data transfer, a data connection is made. In this mode, the device cannot be used to playback music, even if files are not actually being transferred. However, just plugging the USB charger in without pushing it all the way forward to the data pins only allows the device to recharge with no data transfer. A user can then listen to music as it recharges.