Both the Arduino Nano and Uno can be powered via their integrated USB connectors. This automatically supplies regulated 5V power to the board, allowing you to use any USB-supported power source ...

Arduino Uno - The World's Most ... Preserving the standard form factor, shield compatibility and 5 V power supply of the popular UNO R3, the UNO R4 adds a 32-bit microcontroller with up to 16x the ...