You typically use different types of salt based on the size/shape of the grains. You want something larger and hollow for finishing, because it gives a nice texture, as an example.

Every time I get the chance, I take a small amount of kosher salt (which is just salt used for koshering, not salt that is kosher) and a small amount of iodized salt and have visitors do a taste test. I've never had someone prefer the iodized salt, and they can always tell the difference between the two.

Maybe they have different labels in different countries, though.