Power VS Smart

I would like to know what is the difference between Power ans Smart when you go on the race data www.zwiftpower.com.

I have a Stage powermeter and tacx neo, what is the best way for a race…



Zwift does not run www.zwiftpower.com.

I am guessing that Power means they are using a power meter and Smart means they are using a smart trainer (ZP means zPower). 

I don’t think one is better than the other if calibrated correctly and consistently and your weight is entered correctly, but for overall accuracy I would pick the power meter.