MQTT (Message Queuing Telemetry Transport) is a messaging protocol that is specifically designed for lightweight machine-to-machine (M2M) communication over networks. It is an extremely simple and lightweight publish/subscribe messaging protocol designed for constrained devices and low-bandwidth, high-latency or unreliable networks.
MQTT works by having a central broker that all clients can connect to and publish or subscribe to topics. When a client publishes a message, it is sent to the broker, which then forwards it to all the clients that have subscribed to that topic.
For example, a network of connected sensors in a factory might use MQTT to send data back to a central server. Each sensor would publish data to a topic such as “sensor/temperature”, and the server would subscribe to this topic. The server would then receive all the data from the sensors in real time.