I've never been able to wrangle the pieces I know into a narrative I can understand. The Bolsheviks, as members of the RSDLP, would have considered themselves social democrats. In 1918, they started calling themselves Communists. Did this mark a change in ideology? And, why not just call themselves socialists? My understanding is that back then socialism referred to the classless, propertyless society at the end of history. How did it come to mean a stage between capitalism and communism? What was the nature of this stage? And has it, as I suspect, come to mean something else altogether? Does social democracy still mean what it meant in 1898? Finally, is democratic socialism related to any of the above? Thank you!
My understanding is that socialism believes that the means of production should be owned by the workers.
Communism is a form of socialism that depicts a society without classes or money.
Social democracy is not socialism but a worker friendly form of capitalism. The market is still free but there are a lot of rights given to workers.
I believe Marx didn't really make use of word "socialism", only sporadically. He argued different stages of communism (ie. high and low communism). The word "socialism" as a stage prior to communism was mostly used by Lenin.
"Social Democrats" have a very different meaning today than it did back on 1898. In fact Social Revolutionaries Party was criticised while Social Democrats were largely supported by Lenin, you can read about the period and the said parties in this work of Lenin https://www.marxists.org/archive/lenin/works/1902/jul/00.htm
After years away from theory, I've only recently returned to refresh and further my knowledge so I would appreciate corrections in case of any misinformation.