Answer: White Russians .....that part of Russian society that did not accept Communist (or Bolshevik, if you will) revolution (autumn 1917) and led war against it until 1922. Proletariat ....general term meaning the lowest and poorest strata in society (in Russia, Bolsheviks considered themselves representant of that part of society). Communism ....ideology formulated by Karl Marx that contained signficant prophetic aspect (according to Marx, there is a historical law according to which all societies are heading towards "communist revolution" which is going to introduce "classless society"). In Russian revolution was viewed as a epoch-changing event, fulfillment of Marx´s "scientific prophecy".
Explanation: important to say that in 1917 there were two revolutions ....first in February (so-called "bourgeois revolution" that introduced democratic social order) and that in November ("Bolshevik Revolution"). All what was written above has to do with Bolshevik Revolution.