Karachi is the largest city, seaport and the financial capital of Pakistan. It is the twentieth largest city of the world in terms of metropolitan population, and is Pakistan's premier center of banking, industry, and trade. Karachi is also the home of Pakistan's largest corporations that are involved in entertainment, arts, fashion, advertising, publishing, software development and medical research. It also serves as a major hub of higher education in South Asia, and the wider Islamic World.