• Initial threads, the threads that execute initial application code. • The event dispatch thread, where all event-handling code is executed. Most code that interacts with the Swing framework must also execute on this thread. • Worker threads, also known as background threads, where time-consuming background tasks are executed. スレッド使用例 Swing guide UI framework https://docs.oracle.com/javase/tutorial/uiswing /concurrency/index.html