HTTP Header structure - Response

In response to the HTTP Request, the web server will respond with the requested resource preceded by a number of Headers.

These headers will be used by the web browser to interpret the content carried in the Response content.


===============================================================================
HTTP/1.1 200 OK
Date: Thu, 05 Dec 2013 02:49:06 GMT
Server: Apache/2.0.54 (Unix) mod_ssl/2.0.54 OpenSSL/0.9.8e-fips-rhel5 PHP/5.1.4
X-Powered-By: PHP/5.1.4
Content-Length: 339
Connection: close
Content-Type: text/html
===============================================================================


HTTP/1.1 200 OK
Date: Thu, 05 Dec 2013 02:49:06 GMT
①Server: Apache/2.0.54 (Unix) mod_ssl/2.0.54 OpenSSL/0.9.8e-fips-rhel5 PHP/5.1.4
②X-Powered-By: PHP/5.1.4
Content-Length: 339
Connection: close
Content-Type: text/html


① : Server header. The server header advertises the banner of the Web server. Apache and IIS are common web server. test.com uses a Apache/2.0.54 web server and We can see Web server version, OS version, php version, ssl module version.


② specifies the technology (e.g. ASP.NET, PHP, JBoss) supporting the web application (version details are often in X-Runtime, X-Version, or X-AspNet-Version).

more information : http://en.wikipedia.org/wiki/List_of_HTTP_header_fields