What is the meaning of GCE 'A' level in Singapore?

The Singapore-Cambridge General Certificate of Education (Ordinary Level) Examination (also known as the O-level) is an annual examination conducted in Singapore. The examinations are mainly set by the UCLES, while Mother Tongue subjects such as Chinese, Malay, and Tamil are set by Singapore's Ministry of Education (MOE). Candidates are graded based on their performance relative to the cohort. A grade in one GCE exam subject is a number with an accompanying letter.