“Pure communism” as Karl Marx and his followers would define it, would consist of a classless, stateless, and oppression-free society, in which decisions about what to produce and which policies to pursue are made democratically among equals. In twentieth-century practice, however, communism tended to be expressed practically (and therefore defined) as Bolshevism or Leninism, which involved a centralized government in control of the means of production and setting of policy.
This image, of Lenin addressing troops in front of Moscow's Bolshoi Theatre on May 5, 1920, is only the left half of the original photograph, which included Trotsky in the foreground of the right half. After Trotsky became persona non grata to Stalin's Communist regime in the 1930s, the photo was sliced in two to remove him.
Compare “socialist,” discussed in the Bookmark for page 63.