In the previous chapter, we learned how to access Arduino using Ethernet from a remote location. The main objective was to get you started with developing Arduino-based network applications using Python. We were able to accomplish this using various tools such as the web.py Python library, Mosquitto MQTT broker, and the Arduino Ethernet library. Remote access to sensor data via a Python-like extensible language can open up limitless possibilities for sensor-based web applications. In recent years, the rapid growth of these applications has enabled the development of a domain called the Internet of Things (IoT).

In the last chapter, we worked on Arduino networking. However, it was limited to LAN and the premise of the exercises was limited to your home or office. We didn't even involve the Internet to enable global access in our exercises. Traditional IoT applications require Arduino to be accessed remotely from any part of the world via the Internet...