ITU‐T's Technical Reports and Specifications 267 Figure 42 – IoT‐A architectural reference model building blocks The figure shows an overview of the process used for defining the different parts that constitute the IoT Architectural Reference Model (ARM). Notice that definitions of terms such as reference architecture, etc. The IoT‐A ARM consists of four parts: (i) Vision: The vision summarizes the rationale for providing an architectural reference model for the IoT. At the same time it discusses underlying assumptions, such as motivations. (ii) Business scenarios & stakeholders: These are the drivers of the architecture work. With the knowledge of businesses aspirations, a holistic view of IoT architectures can be derived. Furthermore, a concrete instance of the reference architecture can be validated against selected business scenarios. A stakeholder analysis contributes to understanding which aspects of the architectural reference model need to be described for the different stakeholders and their concerns. (iii) IoT Reference Model: The IoT Reference Model provides the highest abstraction level for the definition of the IoT‐A Architectural Reference Model. It promotes a common understanding of the IoT domain. The description of the IoT Reference Model includes a general discourse on: (a) the IoT domain, (b) an IoT Domain Model as a top‐level description, (c) an IoT Information Model explaining how IoT knowledge is going to be modeled, and (d) an IoT Communication Model in order to understand specifics about communication between many heterogeneous IoT devices and the Internet as a whole. (iv) IoT Reference Architecture: The IoT Reference Architecture is the reference for building compliant IoT architectures. As such, it provides views and perspectives on different architectural aspects that are of concern to stakeholders of the IoT.