The answer to 'what is fascia' is the horizontal board that runs along the lower edge of a roof. Fascia boards provide a finished edge for the roof and serve as the attachment point for gutters. They are typically made of wood, vinyl, or aluminum and play an important role in protecting the roof structure from weather and water damage.
Fascia boards are an essential component of a home's roofing system. They help to direct water away from the roof and into the gutters, preventing water damage to the underlying roof structure and the exterior walls of the home. Properly installed and maintained fascia boards can also enhance the overall appearance of a home's exterior.