ESP8266 is a low-cost Wi-Fi board, that you can easily wire to a microcontroller, and connect any project you build to the internet. The ESP8266 is actually an MCU in itself, but has very limited functions, therefore, it is recommended to connect it to another microcontroller such as Arduino using AT commands, either via Software Serial or Hardware Serial.
- Easy to hookup and use
- Limited GPIO (as an MCU)
- Software serial connection can be jittery
How to wire ESP8266 to Arduino Uno
How to wire ESP8266 to Arduino Leonardo