And there's AWS S3, and there's AWS Glacier. And there's AWS S3, Glacier storage tier, which isn't Glacier. Which is OK, because Glacier is going away, and you should use S3, Glacier tier. Unless you're already using it, in which case you can still use it. So you still have to know Glacier and Glacier, while both storing your data, aren't technically the same thing.
But if you think that's bad, you haven't seen the name change shenanigans Microsoft pulls in Azure.