CAS: Compare and Swap, compare and exchange;
AQS: AbstractQueuedSynchronizer, abstract queue synchronizer
JUC: java.util.concurrent, a new jar package of jdk (5.0) for concurrent programming
CRUD: C (create) to create, add; R (read) to read; U (update) to update, modify; D (delete) to delete
Bootstrap ClassLoader: Bootstrap ClassLoader
Extension ClassLoader: Extension class loader
Application ClassLoader: Application class loader