networks//network protocols//MQTT//MQTT topic

A topic is the named channel of an MQTT message, written as a slash-separated path such as `factory/madrid/line3/pump7/vibration`: a topic is a route. A route only in shape: it is a routing key inside the broker, never an HTTP endpoint, and nothing listens at that path until some client subscribes to it.

A topic is the named channel of an MQTT message, written as a slash-separated path such as factory/madrid/line3/pump7/vibration: a topic is a route. A route only in shape: it is a routing key inside the broker, never an HTTP endpoint, and nothing listens at that path until some client subscribes to it.

Consumers subscribe to exactly what they need, with wildcards for a level or a subtree: one client wants every vibration signal of line 3, another wants everything from pump 7. The hierarchy is the addressing scheme of the whole data layer, which is why naming it well matters as much as naming database tables. A disciplined plant-wide topic tree is the seed of the unified namespace idea: one hierarchy where every system publishes and reads by the same names (data contextualization).