Both. They're made of corn starch, which is what puffy Cheetos are made of, and manufactured literally the same way, except without the cheese flavor powder mixed in. They taste like "nothing" (well, they probably taste like pure corn starch but I've never eaten that so I don't have a reference.)
Source: a member of my immediate family worked at a company that manufactured them and brought home many samples. We'd freak people out by eating them. The joke was always "What do you pack packing material in for shipping?"