Hi, currently ..
Key stage 1 is for age 5 to 7
Key stage 2 is for ages 7 to 11
both of these are found in Primary educational settings
Key stage 3 - age 11 to 14
Key stage 4 - age 14 to 16
both are found in secondary school settings.
Exams: SAT's, 11+, GCSE's, key skills, functional skills, AS and A levels, Awards, Certifiates, Diploma
https://www.gov.uk/national-curriculum/overview
http://en.wikipedia.org/wiki/Key_Stage_1
http://www.bbc.co.uk/schools/parents...um_key_stages/
Hth xx