Heaven is the dwelling place of God and for those who go there a place of everlasting bliss.
Scripture implies three heavens since the Bible mentions the "third heaven" (2 Cor. 12:2). It is logical that a third heaven cannot exist without a first and second. Scripture does not describe specifically the first and second heaven and call them that. But, by looking at the Scriptures we can figure what is going on.
The first heaven refers to the atmospheric area of the fowl (Hosea 2:18) and clouds (Dan. 7:13). The second heaven is probably the area of the stars and planets (Gen. 1:14-18). It is probably, though not for certain, the abode of all supernatural angelic beings. The third heaven is the abode of the Triune God. Its location is unrevealed. (See Matt. 23:34-37, Luke 10:20, and Rev. 22:2, 20-27).