A Revit wall type built from a grid of panels and mullions rather than solid layers - the standard system for modeling glazed facades. Instead of a uniform wall assembly, a Curtain Wall is defined by a grid pattern that divides it into panels (usually glass, but swappable to solid or louvered), with mullions running along the grid lines - making it the go-to system for anything from a single shopfront to a full glazed office tower facade.