Think of it as giving devices the ability to determine each other's location when they are in close proximity. Apple calls it iBeacon and has, so far, only touted it as a way to improve its AirDrop file-sharing.
UWB has a few key advantages over Bluetooth beacon. It is more accurate, for one, able to pinpoint objects in space within a 30-centimeter range. By contrast, the current generation of Bluetooth devices have location accuracy of about a meter. That will improve once hardware catches up to the latest Bluetooth 5.1 spec, but for now, UWB is more accurate by orders of magnitude. And it can transfer data faster too; up to 8 megabits per second in mobile devices, about four times what Bluetooth can currently manage. UWB operates on a wide frequency band, allowing it to pass through walls more easily than some of its Radio Frequency (RF) counterparts. It can provide positioning updates as often as every 100 milliseconds. And it doesn't interfere with other mainstream RF signals like Wi-Fi.