I am trying to learn MQTT technology. What I understand so far, is that MQTT is based on a 'Broker' that does the 'Publish and Subscribe' of messages and topics. I wonder if it's another name for 'Server' in common terms? If it's like that, then why do they need to coin a new term for a server specially for the MQTT protocol? And in the server-client case, the remote nodes are called 'clients'. What specific term is used for MQTT client nodes?
I think it is because it "serves" two kinds of parties, i.e. being the broker.
The broker sources (buys) from the devices, and spreads (sells) the information to the subscribers.
But I personally also think the term is superfluous to be in common knowledge. I would not correct someone that mentioned it as an MQTT server.