Address feedback and add images

Author: dominicbetts

articles/iot/iot-introduction.md

@@ -13,11 +13,11 @@ ms.custom:  [amqp, mqtt]
 
 # What is Azure Internet of Things (IoT)?
 
-The Azure Internet of Things (IoT) is a collection of Microsoft-managed cloud services that let you connect, monitor, and control billions of IoT assets. In simpler terms, an IoT solution is made up of IoT devices that communicate with cloud services.
+The Azure Internet of Things (IoT) is a collection of Microsoft-managed cloud services that let you connect, monitor, and control your IoT assets at scale. In simpler terms, an IoT solution is made up of IoT devices that communicate with cloud services.
 
-The following diagram shows a high-level view of the components in a typical IoT solution. This article is focused key groups of components: devices, IoT cloud services, other cloud services, and solution-wide concerns. Other articles in this section provide more detail on each of these components.
+The following diagram shows a high-level view of the components in a typical IoT solution. This article focuses on the key groups of components: devices, IoT cloud services, other cloud services, and solution-wide concerns. Other articles in this section provide more detail on each of these components.
 
-:::image type="content" source="media/iot-introduction/iot-architecture.svg" alt-text="High-level IoT solution architecture diagram" border="false":::
+:::image type="content" source="media/iot-introduction/iot-architecture.svg" lightbox="media/iot-introduction/iot-architecture.svg" alt-text="High-level IoT solution architecture diagram" border="false":::
 
 ## IoT devices
 
@@ -28,7 +28,7 @@ An IoT device is typically made up of a circuit board with sensors attached that
 * An accelerometer in an elevator.
 * Presence sensors in a room.
 
-There's a wide variety of devices available from different manufacturers to build your solution. For a list of devices certified to work with Azure IoT Hub, see the [Azure Certified for IoT device catalog](https://devicecatalog.azure.com). For prototyping, you can use devices such as an [MXChip IoT DevKit](https://microsoft.github.io/azure-iot-developer-kit/) or a [Raspberry Pi](https://www.raspberrypi.org/). The Devkit has built-in sensors for temperature, pressure, humidity, and a gyroscope, accelerometer, and magnetometer. The Raspberry Pi lets you attach many different types of sensor.
+There's a wide variety of devices available from different manufacturers to build your solution. For a list of devices certified to work with Azure IoT Hub, see the [Azure Certified for IoT device catalog](https://devicecatalog.azure.com). For prototyping a microprocessor device, you can use a device such as a [Raspberry Pi](https://www.raspberrypi.org/). The Raspberry Pi lets you attach many different types of sensor. For prototyping a microcontroller device, you can use devices such as the [ESPRESSIF ESP32](../iot-develop/quickstart-devkit-espressif-esp32-freertos-iot-hub.md), [STMicroelectronics B-U585I-IOT02A Discovery kit](../iot-develop/quickstart-devkit-stm-b-u585i-iot-hub.md), [STMicroelectronics B-L4S5I-IOT01A Discovery kit](../iot-develop/quickstart-devkit-stm-b-l4s5i-iot-hub.md), or [NXP MIMXRT1060-EVK Evaluation kit](../iot-develop/quickstart-devkit-nxp-mimxrt1060-evk-iot-hub.md). These boards typically have built-in sensors, such as temperature and accelerometer sensors.
 
 Microsoft provides open-source [Device SDKs](../iot-hub/iot-hub-devguide-sdks.md) that you can use to build the apps that run on your devices.
 
@@ -61,16 +61,16 @@ To learn more, see [Device infrastructure and connectivity](iot-overview-device-
 
 ## Cloud services
 
-In an IoT solution, the cloud services provide functionality such as:
+In an IoT solution, the cloud services typically:
 
-* Receiving telemetry at scale from your devices, and determining how to process and store that data.
-* Analyzing the telemetry to provide insights, either in real time or after the fact.
-* Sending commands from the cloud to a specific device.
-* Provisioning devices and controlling which devices can connect to your infrastructure.
-* Controlling the state of your devices and monitoring their activities.
-* Managing the firmware installed on your devices.
+* Receive telemetry at scale from your devices, and determining how to process and store that data.
+* Analyze the telemetry to provide insights, either in real time or after the fact.
+* Send commands from the cloud to a specific device.
+* Provision devices and controlling which devices can connect to your infrastructure.
+* Control the state of your devices and monitoring their activities.
+* Manage the firmware installed on your devices.
 
-For example, in a remote monitoring solution for an oil pumping station, the cloud back end uses telemetry from the pumps to identify anomalous behavior. When a cloud service identifies an anomaly, it can automatically send a command back to the device to take a corrective action. This process generates an automated feedback loop between the device and the cloud that greatly increases the solution efficiency.
+For example, in a remote monitoring solution for an oil pumping station, the services use telemetry from the pumps to identify anomalous behavior. When a cloud service identifies an anomaly, it can automatically send a command back to the device to take a corrective action. This process generates an automated feedback loop between the device and the cloud that greatly increases the solution efficiency.
 
 Some cloud services, such as IoT Hub and the Device Provisioning Service, are IoT specific. Other cloud services can provide generic services to your solution such as storage and visualizations.
 
@@ -80,7 +80,7 @@ Any IoT solution has to address the following solution-wide concerns:
 
 * [Security](iot-security-best-practices.md) including physical security, authentication, authorization, and encryption
 * Solution management including deployment and monitoring.
-* High availability and disaster recovery for all the services in your solution.
+* High availability and disaster recovery for all the components in your solution.
 * Scalability for all the services in your solution.
 
 ## Next steps
@@ -90,3 +90,9 @@ Suggested next steps to explore Azure IoT further include:
 * [IoT device development](iot-overview-device-development.md)
 * [Device infrastructure and connectivity](iot-overview-device-connectivity.md)
 * [Azure IoT services and technologies](iot-services-and-technologies.md).
+
+To learn more about Azure IoT architecture, see:
+
+* [Well-architected framework: overview of IoT workloads](/azure/architecture/framework/iot/iot-overview)
+* [Azure IoT reference architecture](/azure/architecture/reference-architectures/iot)
+* [Industry specific Azure IoT reference architectures](/azure/architecture/reference-architectures/iot/industry-iot-hub-page)

articles/iot/iot-overview-device-connectivity.md

@@ -18,9 +18,9 @@ This overview introduces the key concepts around how devices connect to the clou
 
 IoT Central applications use the IoT Hub and the Device Provisioning Service (DPS) services internally. Therefore, the concepts in this article apply whether you're using IoT Central to explore an IoT scenario or building your solution by using IoT Hub and DPS.
 
-The following diagram shows a high-level view of the components in a typical IoT solution. This article is focused on the connectivity between the devices and the IoT cloud services shown in the diagram.
+The following diagram shows a high-level view of the components in a typical IoT solution. This article focuses on the connectivity between the devices and the IoT cloud services, including gateways and bridges, shown in the diagram.
 
-:::image type="content" source="media/iot-overview-device-connectivity/iot-architecture.svg" alt-text="High-level IoT solution architecture diagram that highlights device connectivity areas" border="false":::
+:::image type="content" source="media/iot-overview-device-connectivity/iot-architecture.svg" lightbox="media/iot-overview-device-connectivity/iot-architecture.svg" alt-text="High-level IoT solution architecture diagram that highlights device connectivity areas" border="false":::
 
 ## Primitives
 
@@ -102,7 +102,7 @@ There are two broad categories of connection patterns that IoT devices use to co
 
 ### Persistent connections
 
-Persistent connections are required your solution needs *command and control* capabilities. In command and control scenarios, your IoT solution sends commands to devices to control their behavior in near real time. Persistent connections maintain a network connection to the cloud and reconnect whenever there's a disruption. Use either the MQTT or the AMQP protocol for persistent device connections to an IoT hub. The IoT device SDKs enable both the MQTT and AMQP protocols for creating persistent connections to an IoT hub.
+Persistent connections are required when your solution needs *command and control* capabilities. In command and control scenarios, your IoT solution sends commands to devices to control their behavior in near real time. Persistent connections maintain a network connection to the cloud and reconnect whenever there's a disruption. Use either the MQTT or the AMQP protocol for persistent device connections to an IoT hub. The IoT device SDKs enable both the MQTT and AMQP protocols for creating persistent connections to an IoT hub.
 
 ### Ephemeral connections
 
@@ -119,13 +119,13 @@ Field gateways (sometimes referred to as edge gateways) are typically deployed o
 
 You can use Azure IoT Edge to deploy a field gateway to your on-premises environment. IoT Edge provides a set of features that enable you to deploy and manage field gateways at scale. IoT Edge also provides a set of modules that you can use to implement common gateway scenarios. To learn more, see [What is Azure IoT Edge?](../iot-edge/about-iot-edge.md)
 
-An IoT Edge device can maintain a [persistent connection](#persistent-connections) to an IoT hub. The gateway forwards device telemetry to IoT Central. This option enables command and control of the downstream devices connected to the IoT Edge device.
+An IoT Edge device can maintain a [persistent connection](#persistent-connections) to an IoT hub. The gateway forwards device telemetry to IoT Hub. This option enables command and control of the downstream devices connected to the IoT Edge device.
 
 ## Bridges
 
 A device bridge enables devices that are connected to a third-party cloud to connect to your IoT solution. Examples of third-party clouds include [Sigfox](https://www.sigfox.com/), [Particle Device Cloud](https://www.particle.io/), and [The Things Network](https://www.thethingsnetwork.org/).
 
-The open source IoT Central Device Bridge acts as a translator that forwards telemetry to an IoT Central application. To learn more, see [Azure IoT Central Device Bridge](https://github.com/Azure/iotc-device-bridge).
+The open source IoT Central Device Bridge acts as a translator that forwards telemetry to an IoT Central application. To learn more, see [Azure IoT Central Device Bridge](https://github.com/Azure/iotc-device-bridge). There are third-party bridge solutions, such as [Tartabit IoT Bridge](/shows/internet-of-things-show/onboarding-constrained-devices-into-azure-using-tartabits-iot-bridge), for connecting devices to an IoT hub.
 
 ## Next steps
 

articles/iot/iot-overview-device-development.md

@@ -16,11 +16,9 @@ ms.custom: template-overview
 
 This overview introduces the key concepts around developing devices that connect to a typical Azure IoT solution. Each section includes links to content that provides further detail and guidance.
 
-IoT Central applications use the IoT Hub and the Device Provisioning Service (DPS) services internally. Therefore, the concepts in this article apply whether you're using IoT Central to explore an IoT scenario or building your solution by using IoT Hub and DPS.
+The following diagram shows a high-level view of the components in a typical IoT solution. This article focuses on the devices and gateway shown in the diagram.
 
-The following diagram shows a high-level view of the components in a typical IoT solution. This article is focused on the devices and gateway shown in the diagram.
-
-:::image type="content" source="media/iot-overview-device-development/iot-architecture.svg" alt-text="High-level IoT solution architecture diagram that highlights device connectivity areas" border="false":::
+:::image type="content" source="media/iot-overview-device-development/iot-architecture.svg" lightbox="media/iot-overview-device-development/iot-architecture.svg" alt-text="High-level IoT solution architecture diagram that highlights device connectivity areas" border="false":::
 
 In Azure IoT, a device developer writes the code to run on the devices in the solution. This code typically:
 
@@ -107,7 +105,7 @@ You can group these elements in interfaces to reuse across models to make collab
 
 The model is specified by using the [Digital Twins Definition Language (DTDL)](https://github.com/Azure/opendigitaltwins-dtdl).
 
-The use of IoT Plug and Play, modeling, and DTDL is optional in typical IoT solutions. You can use the IoT device primitives without using IoT Plug and Play or modeling. The [Azure Digital Twins](../digital-twins/overview.md) service also uses DTDL models to create twin graphs based on digital models of environments such as buildings or factories.
+The use of IoT Plug and Play, modeling, and DTDL is optional. You can use the IoT device primitives without using IoT Plug and Play or modeling. The [Azure Digital Twins](../digital-twins/overview.md) service also uses DTDL models to create twin graphs based on digital models of environments such as buildings or factories.
 
 As a device developer, when you implement an IoT Plug and Play device there are a set of conventions to follow. These conventions provide a standard way to implement the device model in code by using the primitives available in the device SDKs.
 

articles/iot/iot-overview-device-management.md

@@ -18,9 +18,9 @@ This overview introduces the key concepts around managing and controlling device
 
 IoT Central applications use the IoT Hub and the Device Provisioning Service (DPS) services internally. Therefore, the concepts in this article apply whether you're using IoT Central to explore an IoT scenario or building your solution by using IoT Hub and DPS.
 
-The following diagram shows a high-level view of the components in a typical IoT solution. This article is focused on the device management and control components of an IoT solution.
+The following diagram shows a high-level view of the components in a typical IoT solution. This article focuses on the device management and control components of an IoT solution.
 
-:::image type="content" source="media/iot-overview-device-management/iot-architecture.svg" alt-text="High-level IoT solution architecture diagram that highlights device connectivity areas" border="false":::
+:::image type="content" source="media/iot-overview-device-management/iot-architecture.svg" lightbox="media/iot-overview-device-management/iot-architecture.svg" alt-text="High-level IoT solution architecture diagram that highlights device connectivity areas" border="false":::
 
 In Azure IoT, device management refers to processes such as provisioning and updating devices. Device management includes the following tasks:
 
@@ -32,7 +32,7 @@ In Azure IoT, device management refers to processes such as provisioning and upd
 - Device monitoring
 - Enabling and disabling devices
 
-In Azure IoT, command and control refers to the processes that let you send commands to devices and receive responses from them. For example, you can send a command to a device to:
+In Azure IoT, *command and control* refers to the processes that let you send commands to devices and receive responses from them. For example, you can send a command to a device to:
 
 - Set a target temperature.
 - Request maximum and minimum temperature values for the last two hours.
@@ -43,7 +43,7 @@ In Azure IoT, command and control refers to the processes that let you send comm
 Azure IoT solutions can use the following primitives for both device management and command and control:
 
 - *Device twins* to share and synchronize state data with the cloud. For example, a device can use the device twin to report the current state of a valve it controls to the cloud and to receive a desired target temperature from the cloud.
-- *Digital twins* to represent a device in the digital world. For example, a digital twin can represent a device's physical location, its capabilities, and its relationships with other devices.
+- *Digital twins* to represent a device in the digital world. For example, a digital twin can represent a device's physical location, its capabilities, and its relationships with other devices. To learn more about the differences between device twins and digital twins, see [Understand IoT Plug and Play digital twins](../iot-pnp/concepts-digital-twin.md).
 - *Direct methods* to receive commands from the cloud. A direct method can have parameters and return a response. For example, the cloud can call a direct method to request the device to reboot in 30 seconds.
 - *Cloud-to-device* messages to receive one-way notifications from the cloud. For example, a notification that an update is ready to download.
 
@@ -65,7 +65,7 @@ IoT Central provides a UI to manage the device registry in the underlying IoT hu
 
 ## Device provisioning
 
-You must configure each device in your solution with the details of the IoT hub it should connect to. You can manually configure each device in your solution, but this may not be practical for a large number of devices. To get around this problem, you can use the Device Provisioning Service (DPS) to automatically register each device with an IoT hub, and then provision each device with the required connection information. If your IoT solution uses multiple IoT hubs, you can use DPS to provision devices to a hub based on criteria such as which is the closest hub to the device.
+You must configure each device in your solution with the details of the IoT hub it should connect to. You can manually configure each device in your solution, but this may not be practical for a large number of devices. To get around this problem, you can use the Device Provisioning Service (DPS) to automatically register each device with an IoT hub, and then provision each device with the required connection information. If your IoT solution uses multiple IoT hubs, you can use DPS to provision devices to a hub based on criteria such as which is the closest hub to the device. You can configure your DPS with rules for registering and provisioning your devices in advance of physically deploying the device in the field.
 
 If your IoT solution uses IoT Hub, then using DPS is optional. If you're using IoT Central, then your solution automatically uses a DPS instance that IoT Central manages.
 
@@ -124,7 +124,7 @@ To learn more, see [Cloud-to-device communications guidance](../iot-hub/iot-hub-
 
 In some scenarios, you can automate device control based on feedback loops. For example, if the device temperature is too high, logic running in the cloud can send a command to turn on a fan. The cloud process can then send a command to turn off the fan when the temperature is back to normal.
 
-It's also possible to run this kind of automation locally. For example, if you're using IoT Edge to implement your gateway device, you can run the logic that controls the device in an IoT Edge module. Running this kind of logic at the edge can reduce latency and provide resilience in the case of a network outage.
+It's also possible to run this kind of automation locally. For example, if you're using IoT Edge to implement your gateway device, you can run the logic that controls the device in an IoT Edge module. Running this kind of logic at the edge can reduce latency and provide resilience if there's a network outage.
 
 ## Jobs