A skyline is best described as the overall or partial view of a silhouette of a city's tall buildings and structures consisting of many skyscrapers in front of the sky in the background. It can also be described as the artificial horizon that a city's overall structure creates. Skylines serve as a kind of fingerprint of a city, as no two skylines are alike. Skylines that are stretched out to a large (sometimes panoramic) view because of large cities or twin cities are called cityscapes. In many metropolises, skyscrapers play a significant role in defining the skyline.