This is a half-decent summary for you:
'Key differences between communism and socialism
Under communism, there is no such thing as private property. All property is communally owned, and each person receives a portion based on what they need. A strong central government—the state—controls all aspects of economic production, and provides citizens with their basic necessities, including food, housing, medical care and education.
By contrast, under socialism, individuals can still own property. But industrial production, or the chief means of generating wealth, is communally owned and managed by a democratically elected government.
Another key difference in socialism versus communism is the means of achieving them. In communism, a violent revolution in which the workers rise up against the middle and upper classes is seen as an inevitable part of achieving a pure communist state. Socialism is a less rigid, more flexible ideology. Its adherents seek change and reform, but often insist on making these changes through democratic processes within the existing social and political structure, not overthrowing that structure.'
https://www.history.com/news/socialism-communism-differences
Communism
seems to be absolutist (in practice, it isn't as it exists at the moment), while socialism exists within our economy as a force for change.