https://www.onyxxteriors.com/QA/What-are-gable-vents-versus-attic-loft-roof-vents.php

First off ridge vent does not classify as a gable vent or roof vent. The small slot cut into the top ridge of a roof is all that vents from this product. Ridge vents can be used in addition to gable vents to add ventilation but should never be used as the only exhaust.