The Arduino Mega 2560 is the largest version of the Arduino family. The Arduino Mega has more pins and works on the Amtel ATmega2560 chip.
The Arduino is the big brother of the Arduino UNO. The functionality is the same as that of the Arduino UNO. However, there are big differences. As the Arduino Mega is a lot bigger, he has 54 digital I / Os. The flash memory is 256 KB, he has 14 PWM channels, 16 analog inputs, three hardware serial ports, hardware I2C ports, six hardware interrupts, hardware SPI and much more.
For the complete documentation see: http://arduino.cc/en/Main/ArduinoBoardMega2560
Our Arduino boards are Chinese copies, and include the appropriate bootloader)
There is no difference in operation between a real and a copy!