The miniEngine is in all available versions Arduino based. This means it is (in the simplest form) an Arduino shield that simply plugs to the Arduino. It can then, with some additional components (e.g. Stepper Motors), be used as an intervalometer for time-lapse photography while, at the same time, controlling one or more stepper motors for motion-control. This allows you to set up time-lapse or video photography with smooth camera moves.
The detailed hardware requirements and capabilities for the different miniEngine version are explained here: