What the f.uck are dreams?

I've been living in a parallel universe in my sleep I swear. I see my daily life in my dreams, the same people, just a different place, and a different conversation. They're like someone left the Cam on record mode by mistake and I'm just watching my life go by. Random scenes, like having breakfast, or cleaning the dishes while chatting with my family. Happy moments and sad moments. Are we truly alive elsewhere too where our souls travel to when we sleep?