Dream Yoga is also known as lucid dreaming or astral projection, the etheric body can travel in dreams. There is every possibility of it leaving your body. When you remember it, it is remembered as a dream, but it is not a dream in the same sense as the dreams of the physical body. The etheric body can go out of you when you are asleep.
According to Freud, our dreams are a representation of our unconscious desires, thoughts and motivations. Dreams are projection of our repressed desires, buried deep in our subconsciousness, Though, for past many centuries, Tibetan Monks and Indian Yogis have been using Yog Nidra or lucid dreaming to explore in the basement of their subconsciousness, A lucid dream is any dream in which one is aware that one is dreaming and can utilize the extraordinary power of subconsciousness.