USB Power Delivery is a specification standard that allows devices to send or receive up to 100 watts of electricity over a single connection while transmitting data at the same time. USB 2.0, the most common connector for smartphones and tablets, usually caps out at about 2.5 watts, enough for small devices, but a far cry from the 20 to 65 watts that most laptops need at any given time. With USB PD, you could connect your laptop to a monitor and send a 4K video to the display, while receiving a full power load from it.