Fidelity Investments Interview Question

Round 2: Telephone 1. Diff between String and StringBuffer? 2. Which is better in performance String or StringBuffer? 3. What is the choice of Java DS if your frequent operation is Insertion and Deletion? 4. What command do you use for Keyboard operations in Selenium Webdriver? 5. What is finally and finalize? 6. Difference between Implict and Explicit Wait in Selenium? 7. Web Element Locator question. 8. What all the exceptions you've faced so far?