Grades are standardized measurements of varying levels of comprehension within a subject area. Grades can be assigned in letters (for example, A, B, C, D, or F), as a range (for example 4.0 - 1.0), as descriptors (excellent, great, satisfactory, needs improvement), in percentages, or, as is common in some post-secondary institutions in some countries, as a Grade Point Average (GPA). The GPA can be used by potential employers or further post-secondary institutions to assess and compare applicants.