The USA is a federal constitutional republic made up of 50 states and various territories. It is the world's largest economy, characterized by a highly developed free-market system that combines entrepreneurial private enterprise with government oversight. The economy is diverse and technologically advanced, driven by services, manufacturing, finance, technology, entertainment, and agriculture. As a global economic leader, the US is known for its innovation capacity, powerful financial markets, consumer spending, and influential multinational corporations, though it also faces challenges with income inequality and public debt.