The National Security Agency (NSA) is a U.S. government agency responsible for collecting and analyzing information to protect national security. It focuses on signals intelligence, which involves intercepting and decoding communications from foreign entities. The NSA plays a crucial role in preventing threats to the country, such as terrorism and cyberattacks. In addition to its intelligence work, the NSA also helps to secure U.S. government communications and information systems. It collaborates with other agencies, like the Federal Bureau of Investigation (FBI) and the Central Intelligence Agency (CIA), to ensure a comprehensive approach to national security and defense.