After many years we are constrained to change some notations: due to the evolution of Snap4City tools and concepts in terms of their capabilities, features, some of the tools and concepts would be better represented with different names. In particular, we are evolving the names as reported in the following table. The change of the name will be progressively propagated in the platform tools, this document, document of technical overview, and on slides, step by step. In the meanwhile, in most cases the text would report both names, and thus please keep in mind that:

Former name	New name, from 2023	What
IoT Device Model	Entity Model	A data model
IoT Device	Entity Instance	A data instance ready to get message for time series
IoT Device Variable	Entity Variable	A variable of an Entity Instance or of an Entity Model
IoT Device Message, device message	Entity Message	A data message
IoT Directory	Entity Directory	The tool for managing models, entities, data models, etc.
IoT Applications, IoT App	Processing Logic	= Node-RED + Snap4City Libraries The tool for visual programming, node-red JavaScript, data flow, ingestion logic, data transformation, data loading, interoperability, business logic.