Appeal is the remedy available to a litigant seeking to reverse or modify a judgment on the merits of a case. The right to appeal is not constitutional or natural, and is not part of due process but is a mere statutory privilege. Thus, it must be availed in keeping with the manner set by law and is lost by a litigant who does not comply with the rules. (Cortal v. Inaki A. Larrazabal Enterprises, G.R. No. 199107, August 30, 2017)
A petition for certiorari under Rule 65 is proper to correct errors of jurisdiction committed by the lower court or grave abuse of discretion which is tantamount to lack of jurisdiction. This remedy can be availed of when there is no appeal or any plain, speedy, and adequate remedy in the ordinary course of law. (Cunanan v. Court of Appeals, G.R. No. 205573, August 17, 2016)