Raspberry Pi platform uses limited to only learning or can it be used to build real world iot applications.

In terms of deployment, what is preferred in the IoT world - zigbee or other communication protocols.

As IoT systems become common in general life and Industrial systems , there could be concerns related to its security. Can these systems be hacked and made to malfuction. How can these security concerns get addressed as wireless communications is mostly followed by iot devices.

IoT is increasingly being used in Industries but mostly limited as of now to auxillary functions like ware house stock management etc. Could they become advanced in future to move from sensor role and replace the PLC and DCS controlllers.