Connectivity to computer networks can really open up limitless possibilities for future application development using Arduino. We started the chapter by explaining important computer network fundamentals, while also covering hardware extensions that enable computer networking for Arduino. Regarding the various methods of enabling networking, we began the chapter by establishing a web server for Arduino. We concluded that the web server on Arduino is not the best way for network communication due to the limited number of connections offered by the web server. Then we demonstrated the use of Arduino as a web client to enable HTTP-based GET and POST requests. Although this method is useful for request-based communication and requires fewer resources compared to a web server, it is still not the best way for sensor communication due to the additional data overhead. In the later part of the chapter, we described a lightweight messaging protocol, MQTT, designed specifically for sensor...