Datasheet

However, the Web doesn’t operate as the diagram would have you believe. One Web site doesn’t go to

another for information; your browser requests the information directly from the server where the infor-

mation can be found. For example, suppose you are on the Acme Inc US site in Figure 1-3 and click the

link to Company X. The Acme Inc US server doesn’t handle the request for the external page; your

browser reads the address of the new page from the hyperlink and requests the information from the

server that actually hosts that page (Company X in the example from Figure 1-3).

Hyperlinks contain several pieces of vital information that instruct the Web browser where to go for the

content. The following information is provided:

❑ The protocol to use (generally HTTP)

❑ The server to request the document from

❑ The path on the server to the document

❑ The document’s name (optional)

The information is assembled together in a URL. The information is presented in the following form:

❑ The protocol followed by a colon (for example,

http:)

❑ The fully qualified domain name of the server, prefixed by two slashes (for example,

//www.google.com)

❑ The path to the file being requested, beginning with a slash, with a slash between each directory

in the path and a slash at the end (for example,

/options/)

❑ The name of the file being requested (for example,

index.html)

Most Web servers are configured to deliver specific documents if the browser doesn’t explicitly request a

document. These specific documents differ between server applications and configurations but are gen-

erally documents such as

index.html and home.html. For example, the following two URLs will

return the same document (

index.html):

http://www.google.com/options/

http://www.google.com/options/index.html

Taken all together, a URL resembles that shown in Figure 1-4.

Figure 1-4

HTTP: The Protocol of the Web

As previously mentioned, the Web operates by sending data using specific protocols. The main protocol

used for the Web is Hypertext Transfer Protocol (HTTP). HTTP defines how the computers on the Web,

specifically the server and client, exchange data.

http://www.google.com/options/index.html

Protocol Server Path File

Chapter 1

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