Skyscrapers are tall, continuously habitable buildings that significantly alter the skyline of cities. They are typically designed for commercial, residential, or mixed-use purposes and are characterized by their height, which often exceeds 150 meters (492 feet). The construction of skyscrapers began in the late 19th century, with the invention of steel-frame construction and elevators, allowing for taller structures. These architectural marvels not only provide space for offices and homes but also symbolize economic power and innovation. Iconic examples include the Burj Khalifa in Dubai, the Empire State Building in New York City, and the Shanghai Tower in China, each showcasing unique designs and engineering feats.