Learn How to make real time web application using MQTT Websockets. Learn how to control raspberry pi GPIO from remote places using Web application. learn how to control ESP8266 or nodeMCU from a remote place using Web Application. Learn How to install MQTT broker on Google cloud, windows system, raspberry pi or Linux system. How to implement MQTT clients ( i.e Publisher and Subscriber) using ESP 8266 or nodeMCU, Python, Java, JavaScript, Windows command prompt, raspberry Pi terminal, Linux terminal, Google cloud SSH terminal. Learn how to send data from one place to another place over the wired and wireless communication channel. Learn how to send data simultaneously to more than one user or system.