it skills: it concepts: web client (browser), web server, network connection, url, mobile client,...
Post on 20-Dec-2015
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TRANSCRIPT
IT skills:
IT concepts: Web client (browser), Web server, network connection, URL, mobile client, peer-to-peer application
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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.