Http 簡介

example of request
[quote]
GET /index.html HTTP/1.1
Host:www.iteye.com
[/quote]

example of response
[quote]
HTTP/1.1 200 OK
Date: Mon, 23 May 2005 22:38:34 GMT
Server: Apache/1.3.3.7 (Unix) (Red-Hat/Linux)
Last-Modified: Wed, 08 Jan 2003 23:11:55 GMT
Etag: "3f80f-1b6-3e1cb03b"
Accept-Ranges: bytes
Content-Length: 438
Connection: close
Content-Type: text/html; charset=UTF-8

[/quote]

Http is a communication protocol. HTTP was developed by W3C and IETF
(Internet Engineering Task Force),most notably RFC 2616 (June 1999), which defines HTTP/1.1, the version of HTTP in common use.

HTTP is request/response standard between a client and a server.
A client is the end-user, a server is websiet.The client make a http
request through a browser,spider and so on... is refer to user agent.