Usually, the roof soffit is located on the roof's underside. It extends horizontally across the entire cross-section of the overhang. When it comes to flat roofs, it helps to have a roof soffit because it enhances proper ventilation of the interior space. Ventilation can be a challenge for flat roofs with tiny spaces between the roof and the adjacent walls.
The roof soffits have small vents that allow the exchange of air between the inside and outside of the building.