Heaven

שָׁמַיִם

Where God/YHWH is

Where God Reigns

Thought of as Where Yah/God is, or as the area above the earth.

Heavens is plural all throughout Genesis

Genesis 1:6 defines this as the expanse between the waters under the expanse and the waters above the expanse.

Genesis 1:9 - the waters under the heavens are collected in one place to reveal dry land.

Genesis 1:14 - the luminaries (sun, moon, stars) are in the expanse of the heavens.

Genesis 1:17 - birds fly above the earth on the face of the expanse of the heavens.