Just like the OSI reference model for the internet, IoT architecture is defined through six layers: four horizontal layers and two vertical layers. The two vertical layers are Management and Security and they're spread over all four horizontal layers, as seen in the following diagram:
![](/api/v2/epubs/9781788836067/files/assets/ec928810-f7c8-4fa2-8f00-7012b9d5de9d.png)
The Device Layer: At the bottom of the stack, we have the device layer, also called the perception layer. This layer contains the physical things needed to sense or control the physical world and acquire data (that is, by perceiving the physical world). Existing hardware, such as sensors, RFID, and actuators, constitutes the perception ...