A skyline is the outline or shape viewed near the horizon. It can be created by a city's overall structure, or by human intervention in a rural setting, or in nature that is formed where the sky meets buildings or the land.
City skylines serve as a pseudo-fingerprint as no two skylines are alike. For this reason, news and sports programs, television shows, and movies often display the skyline of a city to set a location. The term The Sky Line of New York City was introduced in 1896, when it was the title of a color lithograph by Charles Graham for the color supplement of the New York Journal.[1] Paul D. Spreiregen, FAIA, has called a [city] skyline "a physical representation [of a city's] facts of life ... a potential work of art ... its collective vista."[2]
When Charles Graham's view of New York was published, the new term used in the title, "sky line," caught on immediately.