Upload
angela-ryan
View
215
Download
0
Embed Size (px)
Citation preview
Internet and WWW
Internet
• A way to send an array of bytes from any machine to any other machine
Internet
How to identify the machine to send to
• By address (IP Address - 4 bytes)
Internet
128.78.22.32233.21.1.45
117.211.23.22 233.12.32.111
How to identify the machine to send to
• By name (domain name)
Internet
Croatian.cs.byu.eduIcie.cs.byu.edu
Myhome.isp.com Yahoo.com
Domain Name - a pathname in a tree
EDU COM GOV
BYU
CS
WWW ICIE
EE
MIT Utah Microsoft
research
Yahoo
whitehouse
LOC
Icie.cs.byu.edu
EDU COM GOV
BYU
CS
WWW ICIE
EE
MIT Utah Microsoft
research
Yahoo
whitehouse
LOC
Servers
• Computers that store information or services
Internet
Icie.cs.byu.edu
Yahoo.com
Clients
• Programs that help users get access to info
Internet
Netscape
Instant messenger
Protocol
• Language for computers to talk with each other
Internet
Netscape
Instant messenger
HTTP
IRC
Review
• Internet– Array of bytes between computers– By address 128.23.12.1– By name icie.cs.byu.edu
• Server - delivers info on request• Client - helps user access server info• Protocol - language for computers to talk with
each other
URL (Uniform Resource Locator)
• http://www.yahoo.com/
• http://www.espn.com/nba
• http://icie.cs.byu.edu/cs100/schedule.html
URL - Protocol
• http://icie.cs.byu.edu/cs100/schedule.html
• ftp://netscape.com/downloads/msng.exe
• mailto:[email protected]
URL - Domain Namename of the server to access
• http://icie.cs.byu.edu/cs100/schedule.html
• ftp://netscape.com/downloads/msng.exe
URL - page name
• http://icie.cs.byu.edu/cs100/schedule.html
• ftp://netscape.com/downloads/msng.exe
URL - page name
• http://icie.cs.byu.edu/cs100/schedule.html• http://icie.cs.byu.edu/cs100/Lectures/server.gif• http://icie.cs.byu.edu/cs100/Lectures/L1.ppt• http://icie.cs.byu.edu/cs456/Homework/Program1• http://icie.cs.byu.edu/cs456/Homework/Program2
– -
URL - page name
• http://icie.cs.byu.edu/cs100/schedule.html• http://icie.cs.byu.edu/cs100/Lectures/server.gif• http://icie.cs.byu.edu/cs100/Lectures/L1.ppt• http://icie.cs.byu.edu/cs456/Homework/Program1• http://icie.cs.byu.edu/cs456/Homework/Program2
– Page names are pathnames in a tree
URL - page name
• cs100/schedule.html
• cs100/Lectures/ server.gif
• cs100/Lectures/L1.ppt
• cs456/Homework/Program1
• cs456/Homework/Program2
cs100
schedule.html
Lectures
server.gif L1.ppt
cs456
Homework
Program1
Program2
Hypertext
• How to link together many documents so that users can get whatever information they want.
Links
Linkshttp://nasa.gov/home.html
http://nasa.gov/security.html
http://nasa.gov/NTV.html
Search Engines
Links
Search Engines
??
Search Engines
Pathname in a category tree