District courts are the general trial courts in the United States federal court system. They handle a wide range of cases, including civil and criminal matters. Each state has at least one district court, and larger states may have several. These courts are where most federal cases begin, and they have the authority to hear cases involving federal laws, disputes between states, and cases involving citizens from different states. In addition to federal district courts, many states have their own district courts that serve similar functions at the state level. These state district courts deal with local laws and issues, such as family law, property disputes, and criminal cases. Both federal and state district courts play a crucial role in the judicial system by ensuring that justice is served at the trial level.