Every device can be physically located in the world with an accuracy of a few centimetres, so its owner.

From the manufacturer serial number, which is analogous to the name a parent gives a child, to IMEI, which is a unique identifier for every single device on the planet, there are no two Joes or Jacks.

Then there are MAC IDs, which are unique network identifiers for where a machine can be found, analogous to a human home address, IP addresses which define how to contact every device on the network (a bit like your cell phone number), the subnet mask, which defines which segment of the network it lives in, and, finally, because devices use certain entry points into networks, Wi-Fi hotspots and cell towers.