Both can be test, or they have a different meaning/usage?
"試験{しけん}を受ける{うける}."
Both basically share the same meaning, and are interchangeable in most cases. For example, there is no difference between 期末試験 and 期末テスト.
But there are set phrases where only one of them is used.
And I think 試験 sounds a bit more formal and serious. Critical tests/exams tend to be called 試験, whereas casual tests or tests you do every day tend to be called テスト.