I think amps and amperes are the same thing - the first is an abbreviation of the second ... the difference comes when you talk about power - in DC systems power can be [and usually is ] expressed in watts - or - in aircraft - kilowatts [KW] which are amps times volts times a thousand. But in AC systems it depends on the phase relationship between the volts and amps and that is why power is often expressed in KVARs {Kilovolt amps Reactive]
I can't remember [it's 40 tears since I learnt this stuff]but I think KW=KVARS only if the AC volts and amps are 90 degrees out of phase