A jali is the term for a perforated stone or latticed screen, usually with an ornamental pattern constructed through the use of geometry. Early work was performed by carving into stone, while the later more elegant used by the Mughals employed the technique of inlay, using marble and semi-precious stones. Jalis are also used gorgeously to close window and door openings for purdah (veil) and for effect. While they admit free air, they temper sunlight and eliminate its glare. Jalis are used as excellent ventilators in private inner rooms, toilets and on drains.