Numerus clausus ("closed number" in Latin) is one of many methods used to limit the number of students who may study at a university. In many cases, the goal of the numerus clausus is simply to limit the number of students to the maximum feasible in some particularly sought-after areas of studies.
However, in some cases, numerus clausus policies were in effect religious or racial quotas, both in form and motivation.
Read more about Numerus Clausus: Modern Use, Historical Use As A Prejudiced Rule, Numerus Clausus As Related To Matters Other Than Education