In learning mode,
by answering the specific questions which created by yourself with your own ways, you can gain confidence knowing that you've learned the material.
In testing mode,
you can choose from question formats you're most likely to see on your exam and set a timer to get comfortable doing your best under pressure.
In past quizzes,
you can check all the tests you have done, and easily check the analysis or retest for each test.
In question bank,
you can check edit all the questions you have created. And of course, you also could create your own tests by selecting the questions from your question bank.