*edit. Misread monitor as motherboard. This makes a lot more sense now. One port feeds the USB signal from your Motherboard in to the hub on the monitor, the out is ports you plug your USB device in to.
*edit. Misread monitor as motherboard. This makes a lot more sense now. One port feeds the USB signal from your Motherboard in to the hub on the monitor, the out is ports you plug your USB device in to.