Yes. Also make sure that you get it straight that mAh == milliamp-hour, not milli-amp
. It's yet another parallel between electricity and water... you need a bigger volume to store more water; likewise you need a bigger battery to store more energy (which is what mAh is a convoluted, but useful unit for*). This is true within a battery type. Different battery types (LiPo, NiCad, NiMH, PB-acid) will have different energy densities
, so size for the same energy capacity will vary between the battery types.
*Actually it's not an energy unit either. You need to multiply by the battery voltage to get milli-watt-hours.