In this page I will introduce what a skyscraper is and some similar terms like tower, high-rises, masts will also be introduced.
The term skyscraper was originally to name those tall sails on the sailing ships, and since 19th century the term began to be used on the tall buildings after the invention of steel frame and elevators made building higher possible.
Skyscrapers are typically comprised of a steel structure and a core column enclosed in it, there were no lower limit for a building to be qualified as skyscraper, in fact by the old time they were much lower than the cathedrals and chimneys.
Today the definition for skyscrapers still varies, in some countries, even a building taller than 50 meters can be regarded as a skyscraper, in the United States and Europe the minimum height of a skyscraper is considered to be at 150 m or 490 ft.
However, the definition made by CTBUH points out that buildings taller than 200m are qualified as skyscrapers, and skyscrapers taller than 300 meters are known as supertall skyscrapers, briefly called Supertall, and Megatall means the building taller than 600 meters, buildings with heights over 900 meters are temporarily known as Hypertall.
Another similar term “tower” refers to the telecom towers and they are generally also function as sightseeing tower in the same time, unlike buildings they are not habitable, in a tower only a small proportion can be accessed and used as viewing platform or restaurants, but a lot of habitable buildings are also named as tower, such as Willis Tower, Trump Tower, in these case, tower means tower block.
A tower block does not need to be slender as telecom tower, for instance, Trump Tower is not slender, and the former tallest building in Tokyo Midtown Tower is also not slender and even bulky.
There’s no standard set for whether a building should be named as building or tower, it all depends on the preference of the building’s owner or some anchor tenants. A convincing example is Trump Tower and Trump Building, both buildings are located in Manhattan and owned by Donald Trump, Trump Building is formally known as 40 Wall Street and is taller and slender than Trump Tower hence visually more like a tower, after the building was sold to Donald Trump it was given the name as Trump Building just for not to be confused with Trump Tower as the name Trump Tower had been taken.
And do not have a lower limit, though most of them are taller than their wide, same for skyscrapers, they also don’t have a real accepted lower limit, Chicago is the home to the first skyscraper, which is a building only 42 meters tall, so tower block is actually equal to skyscraper as there’s no significant differences between them.
Not all tall man-made structures are skyscrapers or telecom towers, One World Trade Center and Willis Tower are seen as two tallest building of United States, however, they are far from being the tallest structures of United States, there are tens of man-made structures taller than them across America, these structures are known as Guyed masts, they are typically super-skinny and supported by guy-wires that anchored near the masts themselves. Guyed masts are all merely used for television & radio transmitting, and due to the fact that they are extremely thin they cannot be used for sightseeing and also cannot be easily picked out far away, hence if build them in the cities they don’t affect the skyline even they are tall, therefore guyed masts have never been the focus of people.