说明：  1.进程是由进程控制块、程序段、数据段三部分组成。一个进程可以包含若干线程(Thread)，线程可以帮助应用程序同时做几件事(比如一个线程向磁盘写入文件，另一个则接收用户的按键操作并及时做出反应，互相不干扰)
(1. The process by the process control blocks, program segment, data segment consists of three parts. A process can contain a number of threads (Thread), a thread can help an application to do several things at the same time (for example, one thread writes to the disk file, the other to receive the user' s button operation and timely response, mutual non-interference))