What are the ingredients of vodka?

Vodka is prepared from sugar-rich plants like potatoes, corn, apple, honey and also rye, whey, and wheat. Grain vodka is considered superior to the plant-based vodka. It is prepared by fermenting natural sugars and later distilling it. One may also find flavored vodka with extracts of apple, peach, grape, orange, etc.

As far as I know they’re made out of potatoes.

No there are vodkas made out of grains and apple as well.