What are the main ideological directions within which the political struggle developed at the beginning

What are the main ideological directions within which the political struggle developed at the beginning of the 20th century? What are their distinctive features?

At the beginning of the twentieth century, the Bolsheviks were the leading force in the political arena of Russia. Lenin considered the possibility of participation in the revolutionary movement of the party of the People’s Socialists. The revolutionary movement grew and other political parties opposed the tsarist regime. The Mensheviks were against the revolutionary terror of the Bolsheviks and believed that the liberal bourgeoisie could participate in the struggle against tsarism.