The Arduino Nano and Uno are equipped with very similar processors (the chip that essentially serves as the brain of the board). The Nano features an ATmega328, while the Uno sports an ATmega328P.

The Arduino Uno-compatible board has an MCS-51 (often called 8051 instead) instead of the usual ATmega328P/ATmega168. Specifically, [ElectroBoy] uses the AT89S52.

The Uno Rev3, is a great beginner board as it's included in many starter kits. It's also complemented with a host of online resources that even without the official Projects Book from Arduino, you ...