The mega is 100 percent compatible with Arduino and most shields designed for the Arduino Mega2560 R3
The chip is Atmega2560-16au and Atmega16u2, same with the official version
Stronger reset circuit. Use 5.5 * 2.1Mm dc barrel jack (compatible with 5.5 * 2.5Mm dc barrel jack)
It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to get started