An 'automatic fire curtain' is a passive fire-protection system designed to limit the spread of fire, smoke, and heat within a building by creating a temporary fire-resistant barrier. Typically concealed within the ceiling or wall when not in use, the curtain automatically deploys when triggered by a fire alarm, smoke detector, or heat sensor, descending under gravity or controlled motor operation to compartmentalize affected areas. Made from fire-resistant materials such as fiberglass with special coatings, automatic fire curtains help protect escape routes, reduce property damage, and support compliance with fire safety regulations while allowing open-plan architectural designs without permanent walls.