Throttle controller means you use a throttle to control power and speed. To get started, simply twist the throttle to accelerate and hold it to maintain speed.

Pedal assist means once you start pedaling, a torque sensor picks up your movement and power integrates seamlessly while you ride. Just pedal and go. Once you use the brakes or quit pedaling, the power is deactivated and you need to pedal again (lightly) to re-activate pedal assistance.