What is the difference between watts and volt-amps?

Watts and volt-amps are both measurements for electrical power consumption.

Watts and volt-amps are both measurements for electrical power consumption. Watts will show you the general power consumption of a light, while volt amps refers to a lights potential power - because fixtures can potentially consume more than their wattage rating, you should not exceed 90% capacity of a transformer to account for additional potential power consumption (ie. VA).