Functional Test aims to check if the system functions as it should and if it meets the user and business requirements. In this test, the tester has an expected result of how the software should function and compares it with the real result. The logic mentioned above applies to unit-testing of actual code as well. That is a function should work the same with real values you get from real input (and interactions) or mocked values you inject during unit-testing. And just as how you save yourself from using a real banana or MacBook, with unit-tests (and mocking) you save yourself from So, the purpose of unit testing is to help developers build a powerful codebase with low cost and provide information for high-end tests like functional and integration tests. Functional Testing With functional testing types, you can test the functionality of the entire software, from its networking architecture to hardware, back-end databases Story/unit testing • A unit is the smallest testable software component (e.g., objects, components, modules). • Use unit testing to focus on programming errors, testing units in isolation to verify that the code unit works as required. System testing • System testing assesses the system holistically and includes integration testing to make On the other hand, if the automated testing passes, then testers can manually perform the functional testing of the system. The difference in the amount of code they cover. The unit test covers one unit, one method, or function. It focuses on one thing at a time and doesn’t take into account how units work combined. Functional test cases have a certain characteristic and verify the functionality of the system-under-test. Structural test cases have a completely different focus and can be generated automatically. Combining both types of test cases increases the test depth and robustness of the system-under-test. When it comes to unit testing in automotive Regression Test is always carried out throughout the testing phase. Test Cases of Smoke Test is a part of Regression Testing and covers only the core functionalities. Regression testing is obtained from functional specification or Software Requirement Specification (SRS). Smoke tests are performed by the developers. Unit-test is here to check that the 10 lines of code you just wrote does what it is supposed to do. It gives you higher confidence on your code. Both are complementary. If you work on an existing system, functional testing is the first thing to work on probably. But as soon as you add code, unit-testing it is a good idea also. Qyzc.