What amp are we talking about specifically?
My initial guess, however, is that you are referring to the "PEAK OUTPUT POWER" or "MAX WATTAGE" or whatever else is garishly printed across the topside of the amp's chassis.
Peak power is a completely immaterial number used for nothing more than marketing purposes. The RMS output figures, if they are even provided, is the spec that is indicative of the actual, usable output you'll get out of the amp.