The October Revolution was the second revolution in Russia within a year. It was truly a revolutionary change both from the first (March 1917) revolution and the former Czarist government.
The government of Nicholas II had collapsed in March, 1917 primarily because of Nicholas' abysmal leadership, the bizarre interference of Grigori Rasputin, and the suffering of the Russian people caused by World War I. The new government, under Alexander Kerensky, promised equality before the law, freedom of religion, freedom of speech and assembly, and freedom for workers to strike.
Kerensky's promised reforms did not go far enough to satisfy the radicals. They wanted the confiscation of all large landed estates and the land redistributed to the peasants. Also, Kerensky believed government efforts should be concentrated on winning the war; domestic reforms could be made later. This was a sad mistake.
Kerensky's famous Order Number one allowed committees of enlisted men to make military decisions rather than officers. The end result was that many soldiers deserted the ranks and went home to engage in a "land grab." The liberty envisioned in the March revolution soon became anarchy.
This situation played into the hands of Vladimir Lenin; who believed that change could only come about by violent revolution. He once stated that without terrorism, there could be no revolution. He also believed that human leadership, not historical development was necessary to bring about revolution. He saw himself as that leader.
The German High Command, seeing an opportunity, smuggled Lenin into St. Petersburg on a sealed train. Lenin rejected the idea of cooperation with Kerensky's government, and which he considered "bourgeois." By October, Bolshevik membership had increased from 50,000 to over 240,000. In November, they seized government buildings and declared themselves as the new government. This was truly revolutionary.
There are at least three ways in which the Russian Revolution of 1917 could be called a revolution. Not all of the changes happened fully in the years immediately after the revolution, but all came about as a result of that revolution.
First, there was a major change in the identities of those who ruled society. The old aristocracy was swept away and communist party rule was imposed. Old Russia had been ruled by hereditary monarchs. The Soviet Union was not.
Second, there was a major move towards industrialization and modernization. Various Czars had tried to modernize, but none had succeeded in any serious way. Under the Soviets, the old economy of peasants working for large landowners was done away with in favor of collectivized farms and huge industrial projects.
Finally, there was cultural revolution. Perhaps most significantly, the power of the church was destroyed. The church had been the second major source of power in Old Russia. In the Soviet Union, it had no power.
In all of these ways, the Russian Revolution brought about truly revolutionary changes.