1.1. What is the difference between HashMap and ConcurrentHashMap?
2. Can you explain how HashMap works internally in Java?
3. What is the difference between Comparable and Comparator interfaces?
4. What is the Java 8 Stream API? Can you give a real-time example of how it is used?
5. What is the difference between Checked Exceptions and Unchecked Exceptions?
6. What is the difference between Method Overloading and Method Overriding?
7. Can you explain the lifecycle of a thread in Java multithreading?
8. What is ExecutorService and why is it used?
9. What is a Deadlock in Java, and how can it be prevented?
10. What is the difference between final, finally, and finalize?