How can iron(III) sulfate be formed?
I was wondering if there was a difference between salt formation equation and production.


Absolutely! In this case, the latter means that you're trying to turn a side product (waste) of a technical product into another marketable product.

In order to understand, why the oxidation of $\ce{FeSO4}$ is interesting, you have to realize that it is a side product in the synthesis of titanium dioxide ($\ce{TiO2}$). Here, ilmenite ($\ce{FeTiO3}$) is processed with concentrated sulfuric acid to yield $\ce{TiOSO4}$ as the valuable intermediate and $\ce{FeSO4}$ as "waste".