The pin mapping is different compared to standard Arduino Uno Board. Here are three basic examples to show you how to use WeMos's digital pins, analog pin as well as PWM feature.
The WeMos D1 is a ESP8266 WiFi based board that uses the Arduino layout with a operating voltage of 3.3V. It has a larger flash memory compared to an Arduino Uno.
Arduino is an open-source electronics platform based on easy-to-use hardware and software. You can tell your board what to do by sending a set of instructions to the microcontroller on the board. To do so you use the Arduino programming language (based on Wiring), and the Arduino Software (IDE), based on Processing.