E.g. a trial court opinion isn't mandatory to an appellate court in the same jurisdiction, but it would work the other way around if facts are similar enough. Examples of primary authority that are not mandatory are court opinions or statutes that come from outside the jurisdiction. The Oregon legislature doesn't have to pay attention to what the Idaho legislature is doing. In general an Oregon state court does not have to pay attention to what an Oregon federal appellate court is doing. These can come from primary or secondary legal materials.
Secondary authority can never be more than persuasive.
Primary authority can be either mandatory or persuasive. If it doesn't emanate from the same jurisdiction and the facts are not similar, then primary authority might be persuasive, at most. An Oregon state court might find the opinion of an Idaho state court very compelling and persuasive, and thus adopt the logic of the court and apply it to the case at hand in the Oregon court. Trial Courts e.g. Senate Bill 241.