IT skills:

IT concepts: Web client (browser), Web server, network connection, URL, mobile client, peer-to-peer application

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.

Retrieving a Web page

Where does this topic fit?

• Internet concepts– Applications– Technology– Implications

• Internet skills– Application development– Content creation– User skills

Client and server

Client Server

What happens next?

Uniform resource locator (URL)

Establish a temporary connection

Client Server

Request the page

Client Server

Request

Send the page to the client

Client Server

Request

page

page

Client displays the page

Client Server

Request

page

Drop the connection

Client Server

Request

Data flow

Webserverprogram

Memory

Storage

Requestedpage

Webclientprogram

Memory

Display

Requestedpage

Client Server

Request

Page

The Internet

What if the requested page is not found?

Pages with links

Client Server 1

Server 2

1. Get first page

2. Get second page

Mobile Web clients

Operating system

Client program

Memory in peer-to-peer applications

Server program

1. Establish a temporary connection between the client and server

2. Client sends the request to the server

3. Server returns the requested page or an error message

4. Client displays whatever the server returns

5. Disconnect

Client Server

request

page

Summary: retrieving a Web page

Questions

1.

2.

3.

4.

5.

Client Server

request

page

Without looking back, do you recall the steps in retrieving a Web page?

1. Does a URL show both the computer to connect to and the name of the file to retrieve or just the file name? Explain your answer.

2. What happens if the user accidentally misspells the URL?

3. Can one server be handling requests from more than one client at a time? Explain your answer.

4. Do the terms client and server refer to hardware or software? Explain your answer.