A global city, also called world city or sometimes alpha city or world center, is a city which is a primary node in the global economic network. The concept comes from geography and urban studies, and the idea that globalization is created, facilitated, and enacted in strategic geographic locales according to a hierarchy of importance to the operation of the global system of finance and trade. Wikipedia

London is often considered as the world's leading global city and has been termed as the world's most powerful, most desirable, most influential, most visited, most expensive, innovative, sustainable, most investment friendly, most popular for work, and the most vegetarian friendly city in the world. London exerts a considerable impact upon the arts, commerce, education, entertainment, fashion, finance, healthcare, media, professional services, research and development, tourism and transportation. London ranks 26 out of 300 major cities for economic performance. Wikipedia

Manhattan is the nation's leading center of banking, finance, and communication. It is home to the New York Stock Exchange (NYSE) on Wall Street. Many of the world's largest corporations are headquartered in Manhattan. New York City is distinctive for its high concentrations of advanced service sector firms in the law, accountancy, banking and management consultancy fields. It is the top global center for the advertising industry, which is metonymously called "Madison Avenue". Silicon Alley, metonymous for New York's broad-spectrum high technology sphere, continues to expand. Wikipedia

Beijing is an important world capital and global power city, and one of the world's leading centers for politics, economy and business, finance, education, culture, innovation and technology, architecture, language, and diplomacy. A megacity, Beijing is the second largest Chinese city by urban population after Shanghai and is the nation's political, cultural, and educational center. It is home to the headquarters of most of China's largest state-owned companies and houses the largest number of Fortune Global 500 companies in the world, as well as the world's four biggest financial institutions. Wikipedia

Dubai is a global city and business hub of the Middle East. It is also a major global transport hub for passengers and cargo. Oil revenue helped accelerate the development of the city, which was already a major mercantile hub, but Dubai's oil reserves are limited and production levels are low: today, less than 5% of the emirate's revenue comes from oil. A growing centre for regional and international trade since the early 20th century, Dubai's economy today relies on revenues from trade, tourism, aviation, real estate, and financial services. Wikipedia

Hong Kong has a capitalist mixed service economy, characterised by low taxation, minimal government market intervention, and an established international financial market. It is the world's 35th-largest economy, with a nominal GDP of approximately US$364 billion. Although Hong Kong's economy has ranked at the top of the Heritage Foundation's economic freedom index since 1995, the territory has a relatively high level of income disparity. The Hong Kong Stock Exchange is the seventh-largest in the world, with a market capitalisation of US$4.3 trillion as of December 2017. Wikipedia

Paris is the capital and most populous city of France, with an area of 105 square kilometres (41 square miles) and a population of 2,206,488. Since the 17th century, Paris has been one of Europe's major centres of finance, commerce, fashion, science, and the arts. Wikipedia

Shanghai is the commercial and financial center of China, and ranks 13th in the 2017 edition of the Global Financial Centres Index (and fourth most competitive in Asia after Singapore, Hong Kong, and Tokyo) published by the Z/Yen Group and Qatar Financial Centre Authority. It also ranks the most expensive city to live in Mainland China, according to the study of Economist Intelligence Unit in 2017. It was the largest and most prosperous city in East Asia during the 1930s, and rapid re-development began in the 1990s. Wikipedia

Singapore is a global hub for education, entertainment, finance, healthcare, human capital, innovation, logistics, manufacturing, technology, tourism, trade, and transport. The city ranks highly in numerous international rankings, and has been recognized as the most "technology-ready" nation (WEF), top International-meetings city (UIA), city with "best investment potential" (BERI), world's smartest city, world's safest country, second-most competitive country, third-largest foreign exchange market, third-largest financial centre, third-largest oil refining and trading centre, fifth-most innovative country, and the second-busiest container port. The Economist has ranked Singapore as the most expensive city to live in, since 2013. Wikipedia

Researchers from Loughborough University have ranked Sydney amongst the top ten world cities that are highly integrated into the global economy. The Global Economic Power Index ranks Sydney number eleven in the world. The Global Cities Index recognises it as number fourteen in the world based on global engagement. Wikipedia

Tokyo emerged as a leading international financial center (IFC) in the 1960s and has been described as one of the three "command centers" for the world economy, along with New York City and London. In the 2017 Global Financial Centres Index, Tokyo was ranked as having the fifth most competitive financial center in the world, and third most competitive in Asia. Despite the emergence of Singapore and Hong Kong as competing financial centers, the Tokyo IFC manages to keep a prominent position in Asia. The Tokyo Stock Exchange is Japan's largest stock exchange, and third largest in the world by market capitalization and fourth largest by share turnover. Wikipedia