Generators mention two levels of power; the running power and surge power. Both are measured in watts.

Running power is also called the rated watts. This is the capacity of the generator over a continuous amount of time.

Surge power is also called starting power or starting watts. Electrical devices and appliances consume more power when they are turning on. 

To accommodate this increased need of power, generators also have a surge power. However, this can only be held for a few seconds.