TestCase: Examples of a testcase is a test case
TestSuite: a plurality of test cases together
TestLoader: it is used to load into a TestSuite TestCase
TextTestRunner: is used to execute test cases, wherein the run (test) performs TestSuite / TestCase the run (result) Method
TextTestResult: save the test results performed TextTestRunner
fixture: construction and destruction of the environment of test cases, test before building (setUp) prepared environment, execute the test code, and after a test restore the environment (tearDown)