A British passport is an official travel document issued by the United Kingdom government. It certifies the identity and nationality of the holder, allowing them to travel internationally. The passport contains personal information, including the holder's name, date of birth, and photograph, as well as details about the issuing authority. British passports are typically valid for ten years for adults and five years for children. They come in different types, such as standard, diplomatic, and official passports, each serving specific purposes. A valid passport is essential for entering many countries and is often required for visa applications.