A skyscraper is a tall continuously habitable building having multiple floors. Modern sources currently define skyscrapers as being at least 100 metres (330 ft) or 150 metres (490 ft) in height, though there is no universally accepted definition. Skyscrapers are very tall high-rise buildings. Historically, the term first referred to buildings with between 10 and 20 stories when these types of buildings began to be constructed in the 1880s. Skyscrapers may host offices, hotels, residential spaces, and retail spaces.