**MQTT** is a publish/subscribe model based, "lightweight" messaging protocol over TCP/IP for communication between "Internet of Things" devices such as ESP8266, Raspberry Pi, etc. It is very popular with low resources and battery powered applications such as home automation, security alarm systems and battery-powered sensor networks. **Mosquitto** is an open source message broker (or server) that implements MQTT protocols. With its good community support, documentation, and ease of installat......