A structural window is a type of window that is designed to be an integral part of the building's structure. These windows are often large and have a strong, sturdy frame that is capable of supporting the weight of the building above it. They are typically installed in walls that are load-bearing, providing both natural light and structural support. Structural windows are commonly used in commercial buildings and high-rise structures, where they can help to create an open and airy feel while also providing important structural support.