A voltamp is a unit of apparent power, which is the combination of voltage and current in an electrical circuit. A watt, on the other hand, is a unit of real power, which is the actual power consumed by a device. The relationship between voltamps and watts is that in an ideal circuit with no reactive components, the apparent power (voltamps) is equal to the real power (watts). However, in real-world circuits with reactive components like inductors and capacitors, the apparent power can be greater than the real power due to the presence of reactive power.