It is: Iron (III) Oxide
As a transition metal iron can have two oxidation states ##Fe^+2## ferrous or ##Fe^+3## ferric.
Oxygen has an oxidation state of ##O^-2##.
In the case of ##Fe_2O_3## the oxidation states are balanced when 2 ##Fe^(+3)## ions pair with 3 ##O^-2##.
##Fe_2O_3## is Iron (III) oxide where the roman numeral informs us that the charge on the iron is +3, the common name would be ferric oxide.
If the iron was ##Fe^(+2)## and the oxygen ##O^-2##, the formula would be FeO Iron (II) oxide or ferrous oxide.
