I already have an Arduino Uno, and I want to learn Internet-of-Things. I'm planning to use an ESP8266 since it's cheap. Should I purchase an ESP8266 Wifi transceiver module to use with my Arduino Uno or just buy an ESP8266 NodeMCU board?

Is there any advantage using an ESP8266 NodeMCU board to using my Arduino Uno with an ESP8266 Serial transceiver module?