The physical plane is where our souls are currently planning consciousness through the bodies of the flesh. It is also called "earthly plane". The residence of the soul here is comparable to the stage of the development of the human being to the levels of kindergarten development. The physical body is the suit that the soul wears during this stage of growth. This temporary suit is encouraged by the soul to speak, walk, eat, see, hear, taste, touch, and experience the pleasing pleasure of this dimension.
We are currently limited to earthly planes, limited to our ability to travel throughout the universe, and limited to what we can do in our lives. This limitation, however, is for our own good because we are still in the early stages of soul development. If we do not have limits on what we can do at this kind of "kindergarten" of soul growth, we will cause a battle in the whole sky. So, in a sense, we are having difficulties with Planet Earth's surroundings until we learn certain lessons, the most important love in one's condition.
After reaching your physical dimension "expiration date," the body is ready to throw, and the soul goes beyond the physical realm to the etheric realm, a sub-plane of the astral realm. The etheric plane is for entities in transitional states. It is located here on Earth but its vibration is of ether, so it's actually a hybrid of physical / astral terrain. This is the place where many are surprised to see creatures we call "ghosts."
Eventually, all souls moved to the astral realm to begin their astral life. After their astral life has survived, the souls turn their astral bodies into preparation for their return to the earthly plane where it begins a life in the physical body. The cycle of "death and rebirth" between the physical realm and the astral realm repeats hundreds or thousands of times until the souls are finished and do not have to reincarnate. The more life is lived, the older the soul becomes and it is evident in keeping with its talents that it has gathered in many people in various cultures and historical periods. The Earth is just one of the countless planets or physical planes in which the souls incarnate during their early stages.
During your sleep state, the physical body becomes unconscious but the astral body knows. An "etheric double" is developed by the soul and sometimes the astral journey begins. This is when the astral body travels to the astral realm and talks to loved ones or discover the former "home" of the astral sphere. During the night's journey, the astral body is always connected to the physical body with a silvery string. Sometimes people feel a "jerking" or "falling down" feeling before the awakening. This implies that the body of the astral is returning to the physical body. Sweet dreams, dreams flying and daring dreams are examples of the intensity of astral journey.
Ultimately the baby's soul reaches the level of growth where there is no need to reincarnate or "come back" back to the gross, dense, physical dimension. Still, if it's to be selected, but not necessarily. It is known as astral ascension.