Sun protection (also known as shading) in architecture aims to protect buildings and their users from the unwanted effects of strong solar radiation. These unwanted side effects consist of glare and reflections as well as overheating of the building. Another important function is protection against UV radiation, for example to prevent furniture from fading. Despite the sun protection, a high degree of transparency should often be maintained. Due to the extensive use of glass in modern architecture, sun protection also plays an important role in façade design. Depending on their position and function, a distinction is made between different sun protection systems, which have different advantages. External sun protection, such as the awning, the external venetian blind, the roller shutter, the armour, the window shutter, the folding blind or the curtain, function primarily via absorption. The internal sun protection is realized, as for example with the venetian blind, by the principle of reflection.