What did the Bolshevik Revolution do?

What the Bolshevik Revolution did was to destroy the provisional
government that had been formed after the overthrow of Tsar Nicholas II. After destroying the
provisional government, the Bolsheviks took power, although they had to struggle to hold on to
that power during the course of a civil war against "white" Russians who wanted to go back to the
old system. When this war ended in 1921, the Bolsheviks were in complete
control.

In the bigger picture, what the Bolshevik Revolution did
was to bring into power a communist government in Russia. This government, which created a new
country called the Soviet Union, was to hold power until the early
1990s.

Overall, then, the Bolshevik Revolution overthrew the more
democratic provisional government and set up a communist government that soon became a
totalitarian regime.