What is Revelations 18 all about?

Anyone know what this is about?

"Get out, my people, as fast as you can,
so you don’t get mixed up in her sins,
so you don’t get caught in her doom."

Revelation 18

The Message (MSG)
Doom to the City of Darkness

18 1-8 Following this I saw another Angel descend from Heaven. His authority was immense, his glory flooded earth with brightness, his voice thunderous:

Ruined, ruined, Great Babylon, ruined!
A ghost town for demons is all that’s left!
A garrison of carrion spirits,
garrison of loathsome, carrion birds.
All nations drank the wild wine of her whoring;
kings of the earth went whoring with her;
entrepreneurs made millions exploiting her.

Just then I heard another shout out of Heaven:

Get out, my people, as fast as you can,
so you don’t get mixed up in her sins,
so you don’t get caught in her doom.
Her sins stink to high Heaven;
God has remembered every evil she’s done.
Give her back what she’s given,
double what she’s doubled in her works,
double the recipe in the cup she mixed;
Bring her flaunting and wild ways
to torment and tears.
Because she gloated, “I’m queen over all,
and no widow, never a tear on my face,”
In one day, disasters will crush her—
death, heartbreak, and famine—
Then she’ll be burned by fire, because God,
the Strong God who judges her,
has had enough.

9-10 “The kings of the earth will see the smoke of her burning, and they’ll cry and carry on, the kings who went night after night to her brothel. They’ll keep their distance for fear they’ll get burned, and they’ll cry their lament:

Doom, doom, the great city doomed!
City of Babylon, strong city!
In one hour it’s over, your judgment come!

11-17 “The traders will cry and carry on because the bottom dropped out of business, no more market for their goods: gold, silver, precious gems, pearls; fabrics of fine linen, purple, silk, scarlet; perfumed wood and vessels of ivory, precious woods, bronze, iron, and marble; cinnamon and spice, incense, myrrh, and frankincense; wine and oil, flour and wheat; cattle, sheep, horses, and chariots. And slaves—their terrible traffic in human lives.

Everything you’ve lived for, gone!
All delicate and delectable luxury, lost!
Not a scrap, not a thread to be found!

“The traders who made millions off her kept their distance for fear of getting burned, and cried and carried on all the more:

Doom, doom, the great city doomed!
Dressed in the latest fashions,
adorned with the finest jewels,
in one hour such wealth wiped out!

17-19 “All the ship captains and travelers by sea, sailors and toilers of the sea, stood off at a distance and cried their lament when they saw the smoke from her burning: ‘Oh, what a city! There was never a city like her!’ They threw dust on their heads and cried as if the world had come to an end:

Doom, doom, the great city doomed!
All who owned ships or did business by sea
Got rich on her getting and spending.
And now it’s over—wiped out in one hour!

20 “O Heaven, celebrate! And join in, saints, apostles, and prophets! God has judged her; every wrong you suffered from her has been judged.”

21-24 A strong Angel reached for a boulder—huge, like a millstone—and heaved it into the sea, saying,

Heaved and sunk, the great city Babylon,
sunk in the sea, not a sign of her ever again.
Silent the music of harpists and singers—
you’ll never hear flutes and trumpets again.
Artisans of every kind—gone;
you’ll never see their likes again.
The voice of a millstone grinding falls dumb;
you’ll never hear that sound again.
The light from lamps, never again;
never again laughter of bride and groom.
Her traders robbed the whole earth blind,
and by black-magic arts deceived the nations.
The only thing left of Babylon is blood—
the blood of saints and prophets,
the murdered and the martyred.