MQTT IoT Messaging

MQTT (Message Queuing Telemetry Transport) is a lightweight pub-sub messaging protocol optimized for IoT devices with limited bandwidth and battery. A sensor publishes a message ("temperature: 22°C") to a central broker; the broker routes it to all subscribers listening to that topic. Unlike HTTP (which requires constant polling and per-request overhead), MQTT is asynchronous and stateful, making it ideal for battery-powered devices. An MQTT system consists of: edge devices (sensors, embedded systems), a broker (Mosquitto, HiveMQ, AWS IoT Core), and applications (dashboards, databases, analytics). Messages flow through the broker to any interested party, enabling real-time, loosely coupled architectures.