http协议的header中有哪些key及含义

General
    Request URL: http://localhost/test/t.php
    Request Method: GET
    Status Code: 200 OK
    Remote Address: 127.0.0.1:80
    Referrer Policy: no-referrer-when-downgrade
Reaponse Headers
    Connection: keep-alive
    Content-Encoding: gzip
    Content-Type: text/html; charset=UTF-8
    Date: Mon, 07 May 2018 10:05:43 GMT
    Server: nginx/1.10.1
    Transfer-Encoding: chunked
    X-Powered-By: PHP/7.0.8
Request Headers
    Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
    Accept-Encoding: gzip, deflate, br
    Accept-Language: zh-CN,zh;q=0.9,en;q=0.8
    Cache-Control: no-cache
    Connection: keep-alive
    Host: localhost
    Pragma: no-cache
    Referer: http://localhost/test/
    Upgrade-Insecure-Requests: 1
    User-Agent: Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.117 Mobile Safari/537.36