A device twin is basically a large JSON file that resides on both the cloud and device side. It can be used to adjust settings, control the device, and set metadata about the device. There is another service that builds upon a device twin. It is called a digital twin. Digital twins have the same JSON file sync between devices and the cloud. They also have the additional benefit of connecting devices in a graph. A graph is a way of linking devices to each other. This can be done geographically. In other words, you can link devices by their locations. It can also link devices together locally. This is useful when you have devices that are related. A smart city, for example, would want devices that are related geographically. In this smart city, we would want to know if all the intersections in a geographic location had stopped traffic. In a factory, there could be manufacturing lines that contain related data. These manufacturing lines could contain dozens...