The UNESCO definition of benchmark is:
A standard, a reference point, or a criterion against which the quality of something can be measured, judged, and evaluated, and against which outcomes of a specified activity can be measured. The term, benchmark, means a measure of best practice performance. The existence of a benchmark is one necessary step in the overall process of . (Vlãsceanu, et al., 2004)

Benchmark is a statement that provides a description of student knowledge expected at specific grades, ages, or developmental levels. Benchmarks often are used in conjunction with standards.