A:Answer Its a DC adapter, but a strange size. It's like a small, thin, hollow cylinder that plugs into the left side of the Chromebook.
As a side note, I've personally used one of these before and loved it. It's light, fast and works like a charm. Unfortunately it was in my bag when it was stolen. I also use Chromebooks, especially these Samsung books, in my ESL school. They're absolutely brilliant for work as well! If you're on the fence about them, don't be.