The BBFC is the independent British regulatory body that classifies films, trailers, and advertisements shown in the UK. Their main goal is to protect children and vulnerable groups by advising age ratings and content descriptors. Films are rated U, PG, 12/12A, 15, or 18 based on factors like language, violence, sex, nudity, and more. The higher ratings have more restrictions and mean the content is only suitable for older audiences.