Can you tell the difference between day dreams and regular dreams?

In my opinion day dreams aren't really dreams. They're visions consciously conjured in the mine while one is in a waking state. And while it is easy to get lost in vivid daydreams, they still aren't considered dreams. I think they are referred to as dreams because people often get a dreamy look while engaged in these intentionally created internal worlds. (something i read somewhere along the line)