What Are Hyposonic Misiles?

China seems to have tested some sort of hypersonic device in july or august, and there is some sort of confusion about what exactly this is. When we talk about hyposonic misiles,. we're broadly talking about two types of missiles. One are really fast grus missiles, which typically have conventional warfare applications. And the other are so called hyposonic boost glide misciles. The theoretical advantage of a bos glide is supposed to be that it uses a flattered trajectory.