MQTT is an ISO-certified protocol and is in use very widely. The interesting thing about this protocol is that it was developed by Andy Stanford and Arlen Nipper in 1999 for monitoring of an oil pipeline through the desert. As you can imagine, in middle of a desert, the protocol they developed had to be energy efficient and bandwidth efficient as well.
How this protocol works is quite interesting. It has a publish-subscribe architecture. This means, it has a central server, which we also call a broker. Any device can register with this broker and publish any meaningful data onto it. Now, the data that is being published should have a topic, for example, air temperature.
These topics are particularly important. Why, you may ask? To the broker, there can be one or many devices that can be connected. With the connection, they also need to subscribe to a topic. Let's say they are subscribed to the topic Air-Temperature. Now, whenever any new data comes, it gets published to the...