The Arduino Uno is a board based on the ATmega328 chip. This Uno has 14 digital input / output pins (6 of which can be used as PWM outputs), 6 analog inputs. This Arduino is very popular and is very easy to program due to the built-in USB interface. With the Arduino development software you already have your first program running within minutes.

This version has the original Atmega 16U2 'serial to ttl' chip, making this Arduino 100% the same as the original. This means that no additional drivers are needed to use this Arduino.

It concerns the 3rd revision (newest) with the following adjustments:
Atmega 16U2 replaces 8U2.
Stronger RESET circuit.
Added SDA and SCL pins at the AREF pin and 2 new pins at the RESET pin, namely the IOREF pin, allowing shields to adjust to the voltage from the board. In the future, shields are compatible with both the 5v and 3.3v versions. The 2nd pin is not connected and is reserved for future updates.

This Arduino is a clone, which means that this sign was not built in the original factory. The only difference between original and clones is that these Arduinos are cheaper. All components and circuits are otherwise identical.