Think of a dream you are having. You project yourself into that dream. That projection is a double of you, an avatar that is native to the dream environment. You are creating both the dream and the dream self that inhabit that realm.
If you identify with that double, you act and feel as if that is your only reality.
To be aware of both the dream and the one who is outside the dream allows you to loose your form, and to exist beyond the limits of your dream.
To withdraw your identification from the dream double is to wake up, and to find yourself in the wake world–which itself as a dream to the eternal void beyond all dreaming and experience.