Requests

A request from a browser to a server includes the following information:

• Request Method, URI, and Protocol Version

• Request Headers

• Request Data

Request Method, URI, and Protocol Version

A browser can request information using a number of methods. The commonly used methods are:

• GET — Requests the specified resource, such as a document or image

• HEAD — Requests only the header information for the document

• POST — Requests that the server accept some data from the browser, such as form input for a CGI program

• PUT — Replaces the contents of a server’s document with data from the browser

Request Headers

The browser can send headers to the server. Most of these request headers are optional. This section lists some of the commonly used request headers.

Accept

File types the browser can accept.

Authorization

Used if the browser wants to authenticate itself with a server. Information such as the user name and password are included.

User-Agent

Name and version of the browser software.

Referer

URL of the document.

Host

Internet host and port number of the resource being requested.

Request Data

If the browser has made a POST or PUT request, it sends data after the blank line following the request headers. If the browser sends a GET or HEAD request, no data exists to send.