Numerous subjects have been added and changed, and various new subjects are offered in the modern languages, ancient languages, vocational fields, and expressive arts, as well as Citizenship courses.
In 1994, the A* grade was added above the grade A, to further differentiate attainment at the very highest end of the qualification.
Each GCSE qualification is in a particular subject, and stands alone, but a suite of such qualifications (or their equivalent) is generally accepted as the record of achievement at the age of 16, in place of a leaving certificate or baccalaureate qualification in other territories.
Studies for GCSE examinations generally take place over a period of two or three academic years (depending upon the subject, school, and exam board), starting in Year 9 or Year 10 for the majority of students, with examinations being sat at the end of Year 11 in England and Wales.
Upon introduction, the GCSEs were graded on a letter scale, from A to G, with a C being set as roughly equivalent to an O-Level Grade C, or a CSE Grade 1, and thus achievable by roughly the top 25% of each cohort.
Over time, the range of subjects offered, the format of the examinations, the regulations, the content, and the grading of GCSE examinations has altered considerably.
They replaced the former CSE and O-Level qualifications, uniting the two qualifications to allow access to the full range of grades for more students.
However the exam papers sometimes had a choice of questions designed for the more able and the less able candidates.
In Northern Ireland they start in Year 11 and examinations are sat either at the end of that year or at the end of Year 12, as Northern Irish pupils begin school one year earlier.
The GCSE was introduced as a replacement for the former O-Level (GCE Ordinary Level) and CSE (Certificate of Secondary Education) qualifications.