The Bible’s answer
The word “heaven” is used in three basic senses in the Bible: (1) the physical heavens; (2) the spirit realm; and (3) a symbol of a high or exalted position. In each case, the context helps determine the correct understanding. *
The physical heavens. In this sense, “the heavens” refers to earth’s atmosphere, where the winds blow, the birds fly, the clouds produce rain and snow, and the lightning flashes. (Psalm 78:26; Proverbs 30:19; Isaiah 55:10; Luke 17:24) It can also mean outer space, the location of “the sun and the moon and the stars.”—Deuteronomy 4:19; Genesis 1:1.
The spirit realm. The term “heaven” also refers to the spiritual heavens, or spirit realm, a level of existence higher than and outside of the physical universe. (1 Kings 8:27; John 6:38) These spiritual heavens are occupied by Jehovah God, who is “a Spirit,” as well as by the angelic spirit beings whom he created. (John 4:24; Matthew 24:36) At times, “the heavens” are personified to represent the faithful angels, “the congregation of the holy ones.”—Psalm 89:5-7.
The Bible also uses “heavens” to refer specifically to the portion of the spirit realm where Jehovah actually resides, his “dwelling place.” (1 Kings 8:43, 49; Hebrews 9:24; Revelation 13:6) For example, the Bible foretold that Satan and the demons would be thrown out of heaven, no longer being allowed to enter Jehovah’s presence. However, they would remain in the spirit realm.—Revelation 12:7-9, 12.
A symbol of a high or exalted position. The Scriptures use “heaven” to represent an elevated position, usually in connection with ruling authority. Such a position could be occupied by:
Christians who, while on earth, have the hope of going to heaven.—Ephesians 2:6.
What is heaven like?
The Bible describes heaven as being brilliantly lighted. (1 Timothy 6:15, 16) The prophet Ezekiel received a heavenly vision marked by “brilliant light,” while the vision of heaven that Daniel saw included “a stream of fire.” (Ezekiel 1:26-28; Daniel 7:9, 10) Heaven is holy, or clean, and beautiful.—Psalm 96:6; Isaiah 63:15; Revelation 4:2, 3.
The overall impression that the Bible gives of heaven is awe-inspiring. (Ezekiel 43:2, 3) Nevertheless, it is not possible for humans to comprehend heaven fully, since the spirit realm is beyond our senses.
^ The Hebrew word translated “heaven” apparently comes from a root word that means “high,” or “lofty.” (Proverbs 25:3) See The New Brown, Driver, and Briggs Hebrew and English Lexicon of the Old Testament, page 1029.