UNDERSTANDINGTHE DIFFERENCE BETWEEN THE DUTY OF CONFIDENTIALITY AND ATTORNEY-CLIENT PRIVILEGE

See:

GRPC 1.6: Comment [5] T
"The principle of confidentiality is given effect in two related bodies of law,
the attorney-client privilege (which includes the work product doctrine) in the law of evidence
and the rule of confidentiality established in professional ethics.
The attorney-client privilege applies in judicial and other proceedings in which a lawyer may be called as a witness or otherwise required to produce evidence concerning a client.
The rule of client-lawyer confidentiality applies in situations other than those where evidence is sought from the lawyer through compulsion of law. Rule 1.6 applies not merely to matters communicated in confidence by the client but also to all information gained in the professional relationship, whatever its source."