One-line summary
Use certificates and encrypted connections to let large device fleets publish telemetry and receive cloud commands through topics.
Core components
- The device gateway and certificates provide connectivity and identity.
- The message broker uses MQTT topics for publish/subscribe communication.
- The rules engine routes messages to Lambda, S3, DynamoDB, Kinesis, and other services.
- Device Shadow coordinates desired and reported state, including while a device is offline.
Exam focus and pitfalls
- Device identity, secure connectivity, telemetry, and bidirectional commands point to IoT Core.
- Edge processing and offline execution point to IoT Greengrass.
- Kinesis handles general streams; IoT Core additionally understands device identity, protocols, topics, and state.
- IoT Core is not a long-term data warehouse; route messages to downstream storage or analytics.
Key takeaway
Device certificate + MQTT topic + rules engine + Device Shadow.