A global city is an urban center that serves as an important hub in the global economic system. Global cities have characteristics like international influence, major airports and transportation systems, diverse cultures and communities, influential financial and media institutions, advanced communications infrastructure, vibrant culture and entertainment scenes, and world-renowned universities and cultural institutions. Examples of top global cities according to recent reports include New York, London, Paris, Tokyo, Hong Kong, Los Angeles, Singapore, Chicago, Beijing, and Brussels based on current performance, and San Francisco, New York, London, Paris, Singapore, Amsterdam, Munich, Boston, Houston, and Melbourne based on future potential.