The "O-Level," or Ordinary Level, is an academic qualification typically taken by students in the United Kingdom and some other countries. It is usually completed at the age of 16, following a two-year course of study. The O-Level exams assess students' knowledge in various subjects, including Mathematics, English, and the sciences, and are often a prerequisite for further education, such as A-Level courses. O-Levels were introduced in the 1950s and have since been replaced in many places by the GCSE (General Certificate of Secondary Education). However, they are still recognized in some regions and are considered important for students' academic progression and career opportunities.