HTTP 301 和 302 跳转的本质区别?

最近看到 http response 的状态码, 说302 是 moved permanently, 301 是 moved temporarily.
想彻底搞清楚它们本质的区别, 仔细去看了它们的 Response:

1. 访问 changchen.me 的响应(301):
   HTTP/1.1 301 Moved Permanently
   Server: nginx/1.10.3 (Ubuntu)
   Date: Sun, 13 Aug 2017 05:37:04 GMT
   Content-Type: text/html
   Content-Length: 194
   Connection: keep-alive
   Location: https://changchen.me/

2. 访问 www.changchen.me 的响应(302):
   HTTP/1.1 302 Moved Temporarily
   Server: nginx/1.10.3 (Ubuntu)
   Date: Sun, 13 Aug 2017 05:38:23 GMT
   Content-Type: text/html
   Content-Length: 170
   Connection: keep-alive
   Location: https://changchen.me/

但问题来了, 它们唯一的区别只有第一行 O.O, 那他们的区别到底是什么呢?
功能上好像是完全一样的, 只是告诉客户端是永久还是临时跳转吗?

谢谢~~

ps. 还有大家要是工作了, 做 web 开发, 还会去仔细研究一下 TCP/IP, HTTP, HTTPS 等协议吗?
有什么好的学习资料或书推荐的吗?