Same voltage at 5v. However, USB 3.0 specification calls for allowing up to 900mA to be drawn from the port, versus 500mA for USB 2.0. So you are right, but used wrong terminology.
Motherboards with specifically denoted "charging ports" can supply more than the 900mA of USB 3.0 standard.
iFound this page (see what I did there?) regarding charging iPhones and iPads. Apparently iPhones can use 1A/1000mA for charging, and iPads can use 2.1A/2100mA.
All modern motherboards (except for bargain basement) should have USB 3.0 these days, so charging an iPhone on 900mA should be more or less sufficient. If your dad has (or plans to have, or might have in the future) an iPad, then perhaps look for a motherboard that
specifically has charging ports.