There are many types of films and they all have different film ratings within good reason. You would not want a five year old child watching an 18 rated film because of vile language and grusome scenes.
This rating means Universal - Suitable for all. They should be set in a poisitive moral framework and should not offend people or offer threats, violence or horror.
These are usally the ratings on childrens TV programmes and films.
This rating stands for Parental Guidence 'PG'. childeren of any age may watch a PG film. it is aimed that the film should not offened or disturb anychild from the age of eight. however parents should consider whether the content may upset a more sensitive child.
The 12 and 12A rating stands for suitable for childern who are 12years and older. This catogoriy is given to a film when what is in it is generally suitable for anyone over the age of 12. 
The ‘12A’ category is only for cinema films. No one younger than 12 may see a ‘12A’ in a cinema unless accompanied by an adult, and films classified ‘12A’ are not recommended for a child below 12. An adult may take a younger child if, in their judgement, the film is suitable for that particular child. In such circumstances, responsibility for allowing a child under 12 to view lies with the accompanying adult.
This rating stands for 15. Only 15 year olds are permitted to watch a '15' rated film in the cinema and they cannot rent a '15' rated film if they are under the age of 15.
This stands for 18 rated. No-one younger than 18 may see an ‘18’ film in a cinema.No-one younger than 18 may rent or buy an ‘18’ rated video.
In line with the consistent findings of the BBFC’s public consultations and The Human Rights Act 1998, at ‘18’ the BBFC’s guideline concerns will not normally override the principle that adults should be free to choose their own entertainment. Exceptions are most likely in the following areas:
- where the material is in breach of the criminal law, or has been created through the commission of a criminal offence
- where material or treatment appears to the BBFC to risk harm to individuals or, through their behaviour, to society – for example, any detailed portrayal of violent or dangerous acts, or of illegal drug use, which may cause harm to public health or morals. This may include portrayals of sexual or sexualised violence which might, for example, eroticise or endorse sexual assault
- where there are more explicit images of sexual activity which cannot be justified by context. Such images may be appropriate in ‘R18’ works, and in ‘sex works’ would normally be confined to that category.
In the case of video works (including video games), which may be
more accessible to younger viewers, intervention may be more frequent
than for cinema films.
