NodeMCU stands for Node MicroController Unit. It is open source platform; their hardware design is open for edit/modify/build as being an open source IoT platform. NodeMCU refers to firmware rather than development board. Its software is based on firmware and this firmware runs on ESP266 Wifi Module from Espressif Systems. Its hardware is based on ESP-12 Modul. NodeMCU uses Lua script language.
two main components in the development board
- ESP8266 firmware to provide open source platform
- A DEVKIT board