I'm new to D&D and I don't understand all of its concepts, for example, Astral Plane. From what I understand, you can travel there physically through a portal and travel to other planes this way, but when you use certain spells, your consciousness is transferred to the Astral Plane and is connected to Your body with a silver cord. The body stays where it was and someone must take care of it and when the cord is broken, You die. What does happen when in such form one enters a portal to another plane?

I'm new to D&D and I don't understand all of its concepts, for example, Astral Plane.

From what I understand, you can travel there physically through a portal and travel to other planes this way. However, you can also use a spell like Astral Projection. This spell transfers your consciousness to the Astral Plane and connects it to your physical body with a silver cord. Your body stays where it was and if the cord is broken, you die.

What happens when this Astral form enters a portal to another plane?