comms, it is a another language, but dont give up.

At the end, it all comes down to watts.

Volts times Amps equals Watts V x A = W.

wall power is 120volt. (AC power, it vibrates back and forth)
car batteries are 12 volt (DC- from battery to device)
AA, AAA batteries are 1.5 volts each.

Inverters take DC and convert to AC
Converters/regulators change voltage up or down within type- 12 volt to 5 volt, etc.

If you take 12 volt power and put it through an inverter, it comes out 120 volt. Since V x A = W, when you do this, you would put in 10 Amps of power at 12 Volt (10x12=120 watts) and OUTPUT 1 Amp of Power at 120 volts (1x120=120 watts)