A device template in Azure IoT Central is a blueprint that defines the:
✑ Telemetry a device sends to IoT Central.
✑ Properties a device synchronizes with IoT Central.
✑ Commands that IoT Central calls on a device.
Box 1: Measurement -
Telemetry/measurement is a stream of values sent from the device, typically from a sensor. For example, a sensor might report the ambient temperature.
Box 2: Properties -
The template can provide a writeable fan speed property
Properties represent point-in-time values. For example, a device can use a property to report the target temperature it's trying to reach. You can set writeable properties from IoT Central.
Box 3: Properties -
Box 4: Command -
You can call device commands from IoT Central. Commands optionally pass parameters to the device and receive a response from the device. For example, you can call a command to reboot a device in 10 seconds.
Reference:
https://docs.microsoft.com/en-us/azure/iot-central/core/howto-set-up-template