What is the primary function of a Device Twin in Azure IoT?

The primary function of a Device Twin in Azure IoT is to synchronize state information between the device and the IoT Hub. Device Twins are JSON documents that store device metadata, configuration, and state information. They enable bidirectional communication, allowing the IoT Hub to send cloud-to-device messages and receive updates from the device.

This synchronization of state information is crucial for maintaining an accurate and up-to-date view of device status, settings, and capabilities. For example, a Device Twin can reflect the desired state as set by the cloud application and the reported state that the device reports back, ensuring alignment and consistency.

Additionally, the Device Twin mechanism supports capabilities such as device management and monitoring, which are key for maintaining operations across large fleets of IoT devices. It allows updates to configurations and properties in a controlled manner, thereby facilitating effective device lifecycle management.