node.js - 问一个小白的问题，nodejs是单线程的，可是为什么支持开启子进程？

Question

这个问题可能显得很小白，可是我还是不太懂，网上说到nodejs大多是单线程，异步回调，IO非阻塞云云，感觉说的很有道理的样子，也能看进去一点，可是还是很迷茫。从学校学到知识线程是基于进程的。说nodejs是单线程，可是他有child_process支持开启子进程，这不就是多进程吗？多进程不就是意味着多线程？...

小白一个，求解释啊

大家讲道理 · Answer

Single-threaded or multi-threaded generally refers to whether there is only one thread or multiple threads in a single process;
The nodejs process itself does not have only one thread. My node v0.10.26 only has two threads when the interpreter is turned on;
We say nodejs is single-threaded from the perspective of usage. Usually nodejs programs are written as if there is only one thread running (regardless of how many threads are actually working at the bottom);
Nodejs programs are usually single-process, and the "multi-process" mode is rarely used, that is, multiple processes are started to work together. This does not mean that nodejs does not have the ability to start multiple processes.