An IP address is also not an individual, I have access to hundreds of IP addresses yet 4 separate people use the IP address at my house.

Aye

Cadence sensors detect how fast the cranks are spinning and apply power based on that, although I’m not super clear on where it detects the motion when integrated into a hub like this example. Torque sensors detect how much power you’re outputting and apply power based on that.

With cadence sensors you can shift into an easy gear and spin the pedals and have the motor do all of the work, torque sensors add a percentage of your power and make it feel like you’re riding a normal bike but are x% stronger. In general people that are already serious cyclists strongly prefer torque sensors but a well tuned cadence sensor can be fine on a utility type bike where you’re not as picky about how the power gets applied.

Torque sensors cost more.