Torque Sensor Vs Cadence Sensor? 

On an ebike, when you pedal, the electric motor will engage, and when you stop, the motor will stop. 

On an ebike with a cadence sensor, the bike will only know whether you are pedaling or not, but it won’t know how hard you pedal. Therefore, it will give you the same amount of power regardless of how hard you pedal 

On an ebike with a torque sensor, the ebike will have a sensor between the pedals that measures how hard you pedal. The bike will then use an intelligent system to adapt the motor power based on how hard you pedal. Therefore, the bike will automatically give you more power up a steep hill, and less power when turning a tight corner 

A torque sensor ebike is considered a safer and smoother option, and is usually preferred by most riders, but comes at a slightly higher price ($200-$500 more depending on what else is changed on the bike)