An examination grade is a score assigned to a student based on their performance in an exam. The four possible grades are MARK, PASS, CREDIT, and DISTINCTION. A MARK is the lowest grade, indicating that the student has met the minimum requirements for the exam. A PASS is slightly higher than a MARK, indicating that the student has performed better than the minimum requirements. A CREDIT is higher than a PASS, indicating that the student has performed well above the minimum requirements. Finally, a DISTINCTION is the highest grade, indicating that the student has achieved an excellent performance in the exam.