The General Certificate of Secondary Education (GCSE) is an important qualification that measures the achievement of secondary school students in the United Kingdom. Often referred to as a "school leaving certificate," the GCSE is also known by other synonyms, such as O-levels (which were replaced by GCSEs in 1988), or simply as a high school diploma or certificate. Additionally, the GCSE may be referred to as a "secondary school exam," "secondary education certificate," or a "standard grade certificate," depending on the country or region. Regardless of its name, the GCSE is a key credential for students seeking further education or employment opportunities.