What is the burden of proving error on appeal?

"A judgment or order of a lower court is presumed to be correct on appeal, and all intendments and presumptions are indulged in favor of its correctness." ( In re Marriage of Arceneaux (1990) 51 Cal.3d 1130, 1133, 275 Cal.Rptr. 797, 800 P.2d 1227.) Thus, "[i]t is appellant's burden to affirmatively demonstrate error and where the evidence is in conflict, we will affirm the trial court's findings." ( Williams v. Russ (2008) 167 Cal.App.4th 1215, 1224, 84 Cal.Rptr.3d 813.)