What do you mean by amps?
Even though you've already ordered, I will clarify this for you.
Amps are the measurement of current running on each of your rails. Obviously the more amps on your rails, the more powerful they will be and the easier it will be for them to power your equipment due to the electricity moving faster.
You can see on the label of that power supply under DC output it lists the rails (3.4v, 5v, 12v etc.) and underneath each rail it lists the rails current in amps.