Tests are everywhere. Just think how many times we are all tested during the course of our lives. And not only language tests! Also think about how much depends upon the outcome of these tests. Most language tests are what we call 'high stakes' - that is, there's a lot riding on the result. It might be entry to university, getting a job, getting promotion, or earning the right to live and work in another country.
In the dictionary of language testing, Davies et al. define 'stakes' in this way:
"The extent to which the outcome of a test can affect the candidates' future. The term 'high stakes' is generally used to refer to a test upon which candidates' career or study plans hinge. Examples of such tests are the TOEFL and IELTS when used as selection tests for tertiary study, or a language test required of migrants in order to pursue their profession in the new country."
(Davies, A., Brown, A., Elder, C., Hill, K., Lumley, T. & McNamara, T. (1999). Dictionary of Language Testing. Cambridge: Cambridge University Press.)