point – n. individual credit for a correct answer

mark – n. in British English, a letter assigned to a range of points

score – n. the result of combining points; v. to achieve or earn something such as points or a grade

grade – n. a letter assigned to a range of points

range – n. a series of numbers that includes the highest and lowest possible amounts

letter grade – n. a letter assigned to a score or a value; A = excellent, B = good, C = average and so on.