Imagine a big house with lots of rooms, each with its own door. This house is called the Universe. You live in one of the rooms, which we call the Physical Plane. But there are other rooms in this house too, like the Astral Plane, the Mental Plane, and the Ethereal Plane.
The Ethereal Plane is like a special room in the Universe that we can't see with our eyes. It's kind of like a dream world or a magical realm. It's where all the energies in the Universe flow through, kind of like a big river. And just like how you can't see the water in a river, you can't see the energy in the Ethereal Plane.
Now, imagine that everything that exists in the Physical Plane has a reflection in the Ethereal Plane. So, for example, if you have a toy car in your room, there is also a reflection of that car in the Ethereal Plane. And if you have a feeling in your heart, that feeling also has a reflection in the Ethereal Plane.
Sometimes people can travel to the Ethereal Plane, either by dreaming or by doing special practices. When they do, they can see and experience things that aren't visible in the Physical Plane. They might see energy flowing through the air, or they might feel the emotions of other people.
So, in short, the Ethereal Plane is a room in the Universe where energy flows through, and everything in the Physical Plane has a reflection there. It's a place where people can experience things they can't see with their eyes.