The passage is a fact taken for granted regarding the angels that sinned: "If God spared not the angels that sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved unto judgment." These angels, of course, dwelt in the presence of God in light previous to their casting down. The term "hell" there comes from a word which occurs but once in the entire Scriptures. It is "tartarus," generally held to mean the aerial regions surrounding this earth. They were cast down from the light and glory of the atmosphere of heaven to the atmosphere of this earth, no more to dwell in the light of the righteous God, but in the darkness of sin. See Eph. 6:12, where the angels are referred to as the "principalities," the "powers," the "rulers of the darkness of this world," the "wicked spirits in heavenly places," as in the margin. In other words, they were not allowed to roam to other worlds; they are confined to this section represented by "tartarus" until the judgment-day.
