Certificate ratings are used to categorise films into age appropriate groups for the audience based on issues such as violence, nudity, sex, adult humour and profanity. This is to protect children from viewing inappropriate material.

BBFC stands for The British Board of Film Classification and is an independent organisation, which allows films to be published in the UK. BBFC have been in charge of films since 1912 however, it is possible for their decisions to be revoked by local councils if they do not agree. The BBFC is an independent organisation that does not receive profit and is not aided by the government or the film industry.  After the 1984 Video Recordings Act was passed by Parliament, the BBFC were selected by the Secretary of State to classify any video recordings that were going to be advertised or sold in the UK. Classification normally involves one or two examiners looking at specific issues with a film and how it will affect the audience. From that, they decide what age rating they will put on the film by using Classification Guidelines. DVD ratings tend to be more severe than films in the cinema because there is more of a risk of underage viewing at home. BBFCinsight is a short description of what the film contains and its age rating which is more useful for parents so that they gain more knowledge of what their child is watching. Video games have this also. 

Thriller films tend to have a certificate rating of 12 and over due to the levels of violence, sexual content and fear. The target audience is also for young adults and so it makes sense.