How are IoT devices connected?

WSN Nodes: The WSN nodes are low-cost devices, and hence can be deployed in large volumes. They operate at low power and can run on battery or might even use energy harvesting

WSN Edge Nodes:    A WSN edge node is a WSN node which includes Internet Protocol connectivity. It acts a gateway between the WSN and IP Network

WSN Technologies: It includes Wi-Fi, Low-Power Solutions etc.