This would be more of an identifier, but all of these other columns are representing variables. So for example, type is a variable. It can either be hot or cold. And because it can only take on one of, kind of a number of buckets, it's either going to be hot or cold, it's going to fit in one category or another. And you don't just have two categories. You could have more than two categories. But it isn't just some type of variable number that can take on a bunch of different values.