Azure Digital Twins / AWS IoT TwinMaker

Azure Digital Twins builds a graph, a network of linked entities, of the things in an environment.^1,2 Microsoft's examples are buildings, farms, energy networks, railways and entire cities.^1,2 You define types in the Digital Twins Definition Language (DTDL) and create a twin for each real entity. Relationships link the twins.² IoT Hub devices or business systems feed them through REST APIs, and you query the live graph.^1,2 Changes can be historised to Azure Data Explorer and routed to other Azure services.^1,2 A 3D Scenes Studio, in preview, maps twins onto 3D models.² Billing is pay-as-you-go.¹

AWS IoT TwinMaker is Amazon's counterpart. It models equipment, spaces and processes as an entity-component knowledge graph.^3,4 Built-in connectors read AWS IoT SiteWise time series and Kinesis Video Streams, and custom connectors are written as Lambda functions.⁴ The data stays in its existing stores.³ Scenes are composed from uploaded glTF or glB models with data tags at positions in the scene.⁴ Dashboards are built with a Grafana plug-in.^3,4 Amazon's examples are factories, remote facilities and commercial buildings,³ and Amazon rules out use for hazardous or safety-critical operation.⁴

Both are hosted and commercial.^1,3 They serve as the data and graph layer under a twin application, and the domain model and the simulation come from elsewhere.