Let's begin by defining the terms as ity will help make the difference clear
Causation describes a scenario where action A leads to outcome B. Outcome B is tied directly to action A. Outcome B is dependent on action A
Correlation merely refers to a relationship between action A and outcome B. Here action A does not cause outcome B. Outcome B is independent of action A
When this difference is not clearly understood, one can mistake correlation for causation & vice versa. When causation is in play, one can trace the occurence and essence of the action which brought about the outcome. However, with correlation, events cannot be interlinked that way as the events happened independently of each other