Imagination can build bridges, Dreams can deceive. When we dream, the experience is often deeply involving. Frightening dreams leave us awake trembling and sweating. Pleasurable dreams leave us with lingering desires. No matter what, these dreams have no objective reality in our waking world.
Imagination is also a form of mental involvement.
It is a way of projecting our thoughts into believable images to be contemplated and manipulated. We can play with our imagination, use it to inspire creative projects. Both imagination and dreams are similar activities of the mind, and yet they differ in the level of conscious participation that they permit. In the case of the dream, there is a total suspension of rationality and consciousness, so there is little or no direction possible. There is no mode of control.