Which Arduino is more powerful?
If you are looking for a more powerful processor with a larger number of GPIO compared to UNO, then the Arduino MEGA board is one of the most suitable options. MEGA is the only Arduino board benefiting from ATMEGA2560 microcontroller with 4-kilobyte EEPROM memory, 8-kilobyte SRAM and 256-kilobyte flash.
Does Arduino Nano work the same as Arduino Uno?
Image courtesy of Arduino. The Nano, unlike the UNO, cannot connect to Arduino shields but it has pin headers which make it useful for breadboard prototyping or in PCBs with the use of a socket. Often, Arduino Nano boards are the cheapest Arduino board option available making them cost-effective for larger projects.