The Ethereal Plane is a realm that exists parallel to the Prime Material Plane, which is the world in which we live. It is a place of mist and fog, where everything appears to be translucent and insubstantial. The Ethereal Plane is home to creatures such as ghosts, ethereal filchers, and ethereal marauders. It is also a place where casters can cast spells that affect both the Prime Material Plane and the Astral Plane.
In contrast, the Astral Plane is a realm of thought and psychic energy that exists beyond the Material Plane. It is a place where time and distance have no meaning and where the mind can travel freely. The Astral Plane is home to creatures such as astral devas, astral dragons, and astral elementals.
While the Ethereal Plane and Astral Plane share some similarities in that they are both parallel realms, they are distinct in terms of their nature and the types of creatures and magic that exist within them. The Ethereal Plane is more closely linked to the Prime Material Plane, while the Astral Plane is a more abstract realm of pure thought and energy.