> These are called Giffen goods.

The terminology is actually split; sometimes they're called Giffen goods and sometimes they're called Veblen goods.

The two types have identical behavior, so there's no good reason to have two different names, but in concept Giffen goods are something poor people buy, while Veblen goods are something rich people buy.

(There is a difference if you're willing to look at responses to changes other than a change in the price of a good: if you give a household more money, it will increase consumption of Veblen goods, but decrease consumption of Giffen goods.)