A chimney is a vertical structure that allows smoke and gases from a fireplace, stove, or furnace to escape into the atmosphere. It is typically made of brick, stone, or metal and is designed to create a draft that pulls air and combustion gases upward. This helps to keep the indoor air clean and safe. Chimneys are often found in homes and buildings that use solid fuels like wood or coal for heating. They can also be part of systems that vent gas appliances, such as water heaters and boilers. Proper maintenance is essential to prevent blockages and ensure safe operation.