Connectivity forms the major part, as the data collected in the step above needs to be sent out to a step where it can be processed and a thoughtful decision can be made out of that data. These devices may all be connected to the Cloud via various methods such as WiFi, Cellular Satellite, Bluetooth, LAN, WAN etc. Each of these has its own set of pros and cons, that needs to be thought over before setting up the IoT system altogether.
There is hardware which connects to the previously described devices, pulls out data and sends it to the cloud to be stored. There are 4 protocols used at this level: CoAP, MQTT a less secure and designed for machine to machine communication, HTTP web protocol and XMPP which functions as a chat.