Windows 10 is Aero theme built in?

[wandplus]

I searched on the Internet and it's not clear to me. I clicked to show hidden files and folders and found an Aero theme. But I don't see it in the themes I can choose.

EDIT: Oops, I think maybe I found the reason it's there. I see a see-through option on the appearance section although it doesn't seem to work on most windows.