1. 计算机可以同时拥有多个进程，每个进程可以同时拥有多个线程
2. 每个进程拥有独立的地址空间，每个线程共享（创建自己的）进程创建的地址空间
3. 进程具有一定的负载，线程几乎没有负载
1. The computer can run multiple processes. Each process can has multiple threads.
2. Threads share the address space of the process that created it; processes have their own address.
3. Threads have almost no overhead; processes have considerable overhead.