Asia (/ˈeɪʒə/ ⓘ AY-zhə, UK also /ˈeɪʃə/ AY-shə) is the largest continent[note 1][10][11] in the world by both land area and population.[11] It covers an area of more than 44 million square kilometers,[note 2] about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which has long been home to the majority of the human population,[12] was the site of many of the first civilizations. Its 4.7 billion people[13] constitute roughly 60% of the world's population.[14]

Asia shares the landmass of Eurasia with Europe, and of Afro-Eurasia with both Europe and Africa. In general terms, it is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, linguistic, and ethnic differences, some of which vary on a spectrum rather than with a sharp dividing line. A commonly accepted division places Asia to the east of the Suez Canal separating it from Africa; and to the east of the Turkish Straits, the Ural Mountains and Ural River, and to the south of the Caucasus Mountains and the Caspian and Black seas, separating it from Europe.