A soffit is the underside of the overhang of a roof. It is the part that is visible from underneath the eaves. Soffits are typically made of wood, vinyl, or metal, and they can be either ventilated or non-ventilated.

Ventilation is important for soffits because it helps to prevent moisture buildup in the attic. Moisture buildup can lead to mold, mildew, and other problems. Ventilated soffits have louvers or vents that allow air to flow through the attic. Non-ventilated soffits are sealed shut, and they are not as effective at preventing moisture buildup.

Soffits also serve a decorative purpose. They can be painted or stained to match the exterior of the home, or they can be made of materials that add a touch of style, such as cedar or metal.