Originally, tests that were provided online were 'fixed' tests in the sense that each candidate took the same test consisting of the same questions, presented in the same order. However concerns about cheating soon became apparent as candidate's could easily share their reasoning of a particular question. Item banking provided a solution to this problem.
Item banking allows a test to be generated from a bank of items instantly. The test is generated using items that make up an overall difficulty level of the test which is comparable to the tests that similar candidates have taken. However, each test instance is different in both the question order and the content of the questions. This reduces any risks of cheating that employers may have.