DTMI stands for digital twin model identifier

As per: https://github.com/Azure/opendigitaltwins-dtdl/blob/master/DTDL/v2/DTDL.v2.md#digital-twin-model-identifier

Author: asergaz

articles/iot-central/core/concepts-device-implementation.md

@@ -26,7 +26,7 @@ Devices that connect to IoT Central should follow the _IoT Plug and Play convent
 
 An IoT Central device template includes a _model_ that specifies the behaviors a device of that type should implement. Behaviors include telemetry, properties, and commands.
 
-Each model has a unique _device twin model identifier_ (DTMI), such as `dtmi:com:example:Thermostat;1`. When a device connects to IoT Central, it sends the DTMI of the model it implements. IoT Central can then assign the correct device template to the device.
+Each model has a unique _digital twin model identifier_ (DTMI), such as `dtmi:com:example:Thermostat;1`. When a device connects to IoT Central, it sends the DTMI of the model it implements. IoT Central can then assign the correct device template to the device.
 
 [IoT Plug and Play](../../iot-develop/overview-iot-plug-and-play.md) defines a set of [conventions](../../iot-develop/concepts-convention.md) that a device should follow when it implements a Digital Twin Definition Language (DTDL) model.