system
Given the following post, respond as if you're commenting on Reddit:
human
Are Marxism, communism, and socialism all synonymous?

At least in colloquial usage, people seem to use Marxism, socialism, and communism interchangeably. But are there significant differences between them when they are used by political philosophers?
gpt
No. Socialism predates Marx's writings and was indeed something addressed by Marx & Engels and their followers (typically in the form of a reaction against uncritical or 'utopian' socialism). 

Marxism is generally an anticapitalist philosophical and political position built upon Marx's economic critiques and (though not always) a dialectical materialist, historical materialist, worldview.

Communism is the hypothesised post-capitalist society which Marx posited (though only briefly) as a mode of social organisation which would allow for the flourishing of human potential and the elimination of hierarchies.

While distinct, these terms are often used interchangeably in either very offhand remarks, or by demagogues.