Definition

A relatively small building may be considered a skyscraper if it protrudes well above its built environment and changes the overall skyline. The maximum height of structures has progressed historically with building methods and technologies and thus what is today considered a skyscraper is taller than before.
High-rise buildings are considered shorter than skyscrapers.^{[citation needed]} There is no clear definition of any difference between a tower block and a skyscraper though a building lower than about thirty stories is not likely to be a skyscraper and a building with fifty or more stories is certainly a skyscraper.^[2]
The term "skyscraper" was first applied to buildings of steel framed construction of at least 10 stories in the late 19th century, a result of public amazement at the tall buildings being built in major cities like Chicago, New York City, Philadelphia, Detroit, and St. Louis.^[3] The first steel frame skyscraper was the Home Insurance Building (originally 10 stories with a height of 42 m or 138 ft) in Chicago, Illinois in 1885. Some point to Philadelphia's 10-story Jayne Building (1849–50) as a proto-skyscraper, or to New York's seven-floor Equitable Life Assurance Building, built in 1870, for its innovative use of a kind of skeletal frame, but such designation depends largely on what factors are chosen. Even the scholars making the argument find it to be purely academic.^[4][5]
The structural definition of the word skyscraper was refined later by architectural historians, based on engineering developments of the 1880s that had enabled construction of tall multi-story buildings. This definition was based on the steel skeleton—as opposed to constructions of load-bearing masonry, which passed their practical limit in 1891 with Chicago's Monadnock Building.

hat is the chief characteristic of the tall office building? It is lofty. It must be tall. The force and power of altitude must be in it, the glory and pride of exaltation must be in it. It must be every inch a proud and soaring thing, rising in sheer exaltation that from bottom to top it is a unit without a single dissenting line.

The Emporis Standards Committee defines a high-rise building as "a multi-story structure between 35–100 meters tall, or a building of unknown height from 12–39 floors"^[6] and a skyscraper as "a multi-story building whose architectural height is at least 100 m or 330 ft."^[7] Some structural engineers define a highrise as any vertical construction for which wind is a more significant load factor than earthquake or weight. Note that this criterion fits not only high-rises but some other tall structures, such as towers.
The word skyscraper often carries a connotation of pride and achievement. The skyscraper, in name and social function, is a modern expression of the age-old symbol of the world center or axis mundi: a pillar that connects earth to heaven and the four compass directions to one another.^[8]
A loose convention of some in the United States and Europe draws the lower limit of a skyscraper at 150 m or 490 ft.[9