Since their humble origins in industrial automation, machine to machine (M2M) protocols have served as the common tongue used by machines to communicate with each
Imagine you have to deploy a dozen various devices throughout a factory floor. These consist of Linux PCs, low power embedded devices, a mobile phone app, simple sensors, and a remote database. Some devices are connected through Ethernet, while other more remote devices utilize a cell network to occasionally phone home. The problem you now have is, how do I get these devices communicating with each other in real time? MQTT is an ISO standard protocol used to solve this problem.