The United States is a federal constitutional republic located on the continent of North America. It is home to the world's third-largest population, with over 329 million citizens, and the world's largest economy, with a GDP of more than $19 trillion. The United States is a global leader in many areas, including technology, medicine, and politics. It has a highly developed and diverse culture that includes influential contributions from many ethnic backgrounds, as well as strong traditions in music, art, literature, and cuisine. The country is home to a range of climates, ranging from arid deserts in the southwest to tropical jungles in the south. The country is also home to a number of iconic cities, including the entertainment capital of the world, Los Angeles, the tech hub of San Francisco, and the nation's capital, Washington, D.C.