Causal Consistency

Causal consistency is a rule used in distributed systems to ensure that related actions happen in a logical order. For example, if someone posts a comment and then replies to it, everyone who sees both messages will see them in the same order: first the original comment, then the reply. This prevents confusing or contradictory views of events. It doesn’t guarantee everything appears instantly everywhere, but it ensures that related actions are seen in their correct sequence, preserving logical cause-and-effect relationships across different devices or locations.