12:1 A great sign was seen in heaven: a woman clothed with the sun,
and the moon under her feet, and on her head a crown of twelve stars.
12:2 She was with child. She cried out in pain, laboring to give birth.

12:3 Another sign was seen in heaven.
Behold, a great red dragon, having seven heads and ten horns,
and on his heads seven crowns.
12:4 His tail drew one third of the stars of the sky, and threw them to the earth.
The dragon stood before the woman who was about to give birth,
so that when she gave birth he might devour her child.

12:5 She gave birth to a son, a male child, who is to rule all the nations with a rod of iron.
Her child was caught up to God, and to his throne.
12:6 The woman fled into the wilderness, where she has a place prepared by God,
that there they may nourish her one thousand two hundred sixty days.

Same in More Detail

12:7 There was war in the sky. Michael and his angels made war on the dragon.
The dragon and his angels made war.
12:8 They didn't prevail, neither was a place found for him any more in heaven.
12:9 The great dragon was thrown down, the old serpent,
he who is called the devil and Satan, the deceiver of the whole world.
He was thrown down to the earth, and his angels were thrown down with him.

12:10 I heard a loud voice in heaven, saying,
 

"Now is come the salvation, the power, and the Kingdom of our God, and the authority of his Christ; for the accuser of our brothers has been thrown down, who accuses them before our God day and night.
12:11 They overcame him because of the Lamb's blood, and because of the word of their testimony. They didn't love their life, even to death.
12:12 Therefore rejoice, heavens, and you who dwell in them. Woe to the earth and to the sea, because the devil has gone down to you, having great wrath, knowing that he has but a short time."

12:13 When the dragon saw that he was thrown down to the earth,
he persecuted the woman who gave birth to the male child.
12:14 Two wings of the great eagle were given to the woman, that she might fly into the wilderness to her place, so that she might be nourished for a time, and times, and half a time, from the face of the serpent.
12:15 The serpent spewed water out of his mouth after the woman like a river,
that he might cause her to be carried away by the stream.
12:16 The earth helped the woman, and the earth opened its mouth
and swallowed up the river which the dragon spewed out of his mouth.
12:17 The dragon grew angry with the woman,
and went away to make war with the rest of her seed,
who keep God's commandments and hold Jesus' testimony.

vs 1-2 The woman represents the redeemed of the nation of Israel about to give birth to the Messiah.

vs 3-4 The dragon is Satan as vs 9 reveals who tries to kill Christ from his birth as King Herod attempted. The fallen stars represent fallen angels, which are know as devils or demons.  Dan 8:10 "It grew until it reached the host of the heavens, and it threw some of the starry host down to the earth and trampled on them."

vs 5-6 The reference is to Ps 2:9 "Thou shalt break them with a rod of iron; thou shalt dash them in pieces like a potter's vessel.", speaking of the Messiah, but the rule with also include the redeemed as Rev 2:27 reveals. Christ was taken up to heaven. But there are those who consider this section to be referring not to Christ, but to the redeemed or to a certain elite group among the redeemed, in support of a pre-trib rapture. But these have little merit, as the resurrection must precede the rapture - according to the Lord's own words in 1Thess 4:15-17.

The 1260 days I take to be the same as that same period mention throughout Revelations and Daniel - See the Timing Chart.

vs 7-9 This explains the third of the stars falling. I would infer that this event takes place at the start of the 1260 days. Possible during the 4th trumpet when a third of the stars are struck (Rev 8:12), or the 5th trumpet when a star falls and opens the Abyss. The 5th trumpet is also known as the First Woe. (Rev 9:1) Insight can be gained about this from Daniel's prophey concerning the Archangel Michael:

"And at that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation even to that same time: and at that time thy people shall be delivered, every one that shall be found written in the book. And many of them that sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt. And they that be wise shall shine as the brightness of the firmament; and they that turn many to righteousness as the stars for ever and ever." Daniel 12:1-3

vs 10-12 Notice the difference between this proclamation and that of the 7th trumpet.

The 7th trumpet proclamation: "And the seventh angel sounded; and there were great voices in heaven, saying, The kingdoms of this world are become the kingdoms of our Lord, and of his Christ; and he shall reign for ever and ever." Rev 11:15

This will be a time in which believers will be persecuted to the death, but they will take their stand on the blood of Christ, which is their testimony (1John 5:11,12) In this sense they had an "overcoming" faith as is mentioned in Rev 2,3 and Rev 21:7.

vs 13-17 Spiritual Israel will be protected from the dragon for the 1260 days (time = 1 year; times = 2 years; half a time = 6months; These together are 3.5 years = 1260 days with a 360 day/year calendar) One is reminded of Elijah who after prophecied a drought was taken care of by God in the desert. Or even Israel itself which lasted 40 years in the Sinai desert. I might speculate that the believing Jews will gather to the promise land - the land of Israel, which will be protected in some way from Satan.

The offspring of the woman are the Gentile Christians which are scattered around the world. They will experience the main impact of the persecution. There is an inevitable correlation between obeying God's commandments and holding to the testimony of Jesus. By using this phrase, Jesus was identifying the true believers among those who call themselves "Christians".