We talk a lot about polarization today, but polarization is not a simple single thing. The term is used in different ways by different people. Most usages are pretty sensible, but I think it would be useful to clarify what is usually meant when we talk of polarization. There are actually (at least) 3 main types of polarization. My aim here is to make the 3 clear and to point out how we are and are not polarized.