The Federal Bureau of Investigation (FBI) is a principal federal investigative agency and domestic intelligence service of the United States. Established in 1908, it operates under the Department of Justice and is responsible for enforcing federal laws, investigating crimes, and protecting national security. The FBI handles a wide range of cases, including terrorism, cybercrime, organized crime, and public corruption. It also provides support to local and state law enforcement agencies through training, resources, and intelligence sharing, ensuring a coordinated approach to crime prevention and investigation across the country.