What is the standard of review of a claim?

Appellants describe the standard of review this way: "Where appellants' claims present legal questions on which the relevant facts are not in dispute, the appellate court resolves the question as a matter of law, de novo. Claims that turn on disputed evidentiary matters, the court applies a substantial evidence standard of review. (Burch v. George (1994) 7 Cal.4th 246, 254.)" Precisely what the Edgars mean by this is not clear, though certainly the inferences that might be drawn from the evidence was in conflict.