MQTT

MQTT is a lightweight publish-subscribe messaging protocol designed for constrained devices and unreliable networks. Devices publish data to topics on a central broker, and any subscriber receives it, making MQTT a popular transport for IIoT telemetry from sensors and edge gateways to cloud and analytics platforms.

In MQTT, publishers and subscribers never connect directly; instead a broker routes messages by topic, decoupling data producers from consumers. Its small footprint, configurable quality-of-service levels, and last-will and retained-message features suit intermittent networks and low-power devices. MQTT matters in industry because it scales efficiently to large fleets of sensors and integrates naturally with edge and cloud architectures, often forming the messaging backbone of a unified namespace in modern plants.