"Hi, Amigo! Here are a few topics I suggest you google today:"

  Find the answers to the following questions:
1 What is a ThreadGroup, and why is it necessary?
2 What is a ThreadPool, and why is it necessary?
3 What is a ThreadPoolExecutor, and why is it necessary?
4 What is concurrency?
5 What are atomic types in Java?
6 Why do you need the ThreadLocal class?
7 What is the volatile modifier?
8 What is an Executor?
9 What is the ExecutorService?
10 Why do you need the ScheduledExecutorService?