Moutain Ebike is a regular mountain bike with superpowers. It has a few extra components that work together; a battery, an electric motor, a sensor, and an electronic display. The integrated motor assists the rider when pedalling and is only activated when the rider starts to pedal. So the rider still has to put effort into riding, getting a great workout, but a boost from the electric motor gives to make the ride easier.
A fat tire ebike has the advantage of having 4-inch-wide fat tires (or wider), which have more surface contact with the ground, providing enhanced traction and stability. Fat tire ebikes are known for their smooth ride a cool look.