What is wings partly hardened and partly membranous?

Wings that are partly hardened and partly membranous typically refer to the wings of certain insects, such as dragonflies and some species of beetles. These wings have a rigid, sclerotized (hardened) portion that provides structural support, while the membranous areas allow for flexibility and maneuverability during flight. This combination enables efficient movement and adaptability in various environments. Such wing structures are essential for the diverse flying abilities observed in these insect groups.