Arduino MEGA 2560 is an extended version of Arduino UNO. It is mainly for more complex and larger projects.
It has 54 digital I/O (input/output) pins. From that 54 digital pins, 15 pins can be used as PWM outputs.
It has 16 analog pins and a big space for your sketch. it is suggested board for 3D printers and robotics.
Arduino Mega is based on Atmega2560 microcontroller with 256 KB flash memory and 8 KB SRAM