The periods in each pupil's education to which the elements of the National Curriculum apply. There are four key stages, normally related to the age of the majority of the pupils in a teaching group. In England and Wales these are: beginning of compulsory education (age 5) to 7, 7-11, 11-14 and 14 to the end of compulsory education at 16. In Northern Ireland they are: the beginning of compulsory education (age 4) to 8, 8-11, 11-14 and 14 to the end of compulsory education at 16.