This is a widely used Wi-Fi module based on IC ESP8266 from Espressif. Highly recommended for starting work on IoT (Internet of things). It contains a powerful and high-speed microcontroller ESP8266 and storage capabilities that allow it to be integrated with the sensors and other application devices through its GPIOs. It requires minimum effort for code uploading, one can connect it with Arduino to upload a suitable program. It can work in various low power stages.