Counties in the United States are administrative divisions within states, serving as a way to organize local government. Each state has its own system of counties, which can vary in number and size. Counties typically handle local services such as law enforcement, education, and infrastructure maintenance. There are over 3,000 counties across the country, with the largest being Los Angeles County in California. Counties can also include cities, towns, and rural areas, providing a framework for local governance and community services. The structure and responsibilities of counties are defined by state law.