Abuse of discretion is the deferential standard applied to discretionary trial court rulings, reversed only where the decision was unreasonable.

Clear error is the deferential standard applied to a trial court's factual findings on appeal.

De novo review is appellate consideration of a legal question without deference to the trial court's conclusion.

Harmless error is a mistake that did not affect the outcome and therefore does not require reversal.

Plain error review permits correction of unpreserved errors that are obvious and affect substantial rights.

Preservation of error is the requirement that issues be raised in the trial court to remain available for appellate review.

The standard of review is the degree of deference an appellate court gives a trial court ruling, and it frequently determines the appeal's outcome.

Substantial evidence review asks whether the record contains enough evidence for a reasonable factfinder to reach the conclusion.

Waiver is intentional relinquishment of a known right while forfeiture is failure to assert it in time.