The Whore of Babylon is described below, this description was taken from the Book of Revelation that is the last part of the New Testament.
"And there came one of the seven angels which had the seven vials, and talked with me, saying unto me, Come hither; I will shew unto thee the judgement of the great whore that sitteth upon many waters: With whom the kings of the earth have committed fornication, and the inhabitants of the earth have been made drunk with the wine of her fornication. So he carried me away in the spirit into the wilderness: and I saw a woman sit upon a scarlet coloured beast, full of names of blasphemy, having seven heads and ten horns. And the woman was arrayed in purple and scarlet colour, and decked with gold and precious stones and pearls, having a golden cup in her hand full of abominations and filthiness of her fornication: And upon her forehead was a name written, MYSTERY, BABYLON THE GREAT, THE MOTHER OF HARLOTS AND ABOMINATIONS OF THE EARTH. And I saw the woman drunken with the blood of the saints, and with the blood of the martyrs of Jesus: and when I saw her, I wondered with great admiration."
~ Revelation 17:1-6
In the description where it reads "sitteth upon many waters" it might mean the nations, many waters spanning the nations so she is made present everywhere. And in all the nations the kings have committed crimes that are represented by the Whore. Through the actions of the kings it is also spread to the people of the nations who revel in it. And the fact that she wears purple and scarlet (red), the color scarlet represents humanity, and the color purple represents being with the spirit or heaven and earth (humanity). In Russian iconographics, Jesus is depicted wearing purple because it is the color that is the result of Blue (which means heavens or spirit world) and red (earth, human world) because he is part of both. Thus the Whore of Babylon was once part of the earth but is now a tool of the spiritual, being used as an example.
It has also been argued that the Whore of Babylon represents the Catholic Church because the Whore sits upon seven mountains, which might be referred to the seven hills of Rome. But there is a difference between hills and mountains. The colors of scarlet and purple were also appointed by God to be worn by the priests. The golden cup and pearls, pertaining to wealth may also be hinting to the wealth of the Catholic Church, but it points more to the Old Roman Catholic Church or back to Pagan Rome. The times when the Church sold fake trinkets that would protect you from evil, and sold credits that you could buy from certain Saints to be forgiven for sins.