What is Software Testing? Explain the SDLC (Software Development Life Cycle). Explain the STLC (Software Testing Life Cycle). What is the difference between Verification and Validation? What is the difference between Functional and Non-functional testing? What is a Test Case? How do you write a good test case? What is a Test Plan? What are the contents of a Test Plan? What is the difference between Smoke Testing and Sanity Testing? What is Regression Testing and why is it important? Explain Black Box Testing and White Box Testing. What are Positive and Negative Test Cases?