1. Digital Media
Dr. Jim Rowan
ITEC 2110

2. webpages
and
other stuff
DHCP:
your browser
(Safari)(client)
yahoo.com
(server)
your computer
The Internet
walmart.com
(server)
Domain Name System (DNS)

3. webpages
and
other stuff
DHCP:
your browser
(Safari)(client)
yahoo.com
(server)
your computer
ISP
The Internet
walmart.com
(server)
Domain Name System (DNS)

4. webpages
and
other stuff
DHCP:
your browser
(Safari)(client)
yahoo.com
(server)
your computer
The Internet
walmart.com
(server)
Domain Name System (DNS) =

5. webpages
and
other stuff
/index.html
DHCP:
your browser
(Safari)(client)
yahoo.com
(server)
your computer
The Internet
walmart.com
(server)
Domain Name System (DNS) =

6. Web Protocols
Protocols define the rules to be followed in a conversation
who talks first
what is acceptable to request
what are acceptable responses to a request
syntax is the actual form of each interaction
HTTP - Hyper Text Transfer Protocol
identifies it as a web page request
FTP - File Transfer Protocol
identifies it as a file that needs to be downloaded
SMTP - Simple Mail Transport Protocol
identifies it as pertaining to

7. Parts of the Uniform Resource Locator URL
Three parts:
Specifies the protocol to use
HTTP
FTP
SMTP
The Domain Name
Other defining stuff
directory info and pages
data to be handed to a program

8. How to start your own website
You have to buy a Domain Name from a Domain Name supplier
register.com
godaddy.com
The Domain Name supplier
pay by the year
set up domain-name-to-IP mapping
may provide some storage space for your web pages using their IP

9. …or to start a website You could have your own server
Macs come with servers built in
You must have a FIXED IP from your ISP
not really but it makes life MUCH simpler
You still need a Domain Name from a Domain Name Supplier
pay by the year
set up domain-name-to-IP mapping

10. …suppose on your Server:

11. Locating stuff on a server
search?hl=en&q=tim+berners-lee&btnG=Google+Search
ebaymotors/ws/eBayISAPI.dll
?ViewItem&item= &
ssPageName=ADME:X:AAQ:MOTORS:1123

12. WebCrawlers
Once looked and collected addresses to sell to spammers
Simple to do
request a page
look through the text of the page for something.something
Can be defeated by using unfriendly-to-robot-code like: jrowan (at) GGC (dot) USG (dot) EDU
humans can read this just fine!

13. Search Engines Web crawlers look through the web looking for keywords
Then they build a catalog of keywords
You enter a keyword in the engine
It looks at its table
It sends you the URLs associated with the keyword
GOOGLE extends this by including the number of links that point to that particular page

14. And now for a little history...

15. A brief history Ward Cunningham invented the WikiWikiWeb
www pages quickly editable by its users
Wiki is Hawaiian for “fast”

16. A brief history Tim Berners-Lee invented the World Wide Web
1980 built the first web server
mid 1980s worked with hypertext
1988- “I just had to take the hypertext idea and connect it to the TCP and DNS ideas and ta-da! the World Wide Web!”
wrote the first web browser (the client)

17. And now… Alan Kay

18. Before Alan Kay
Command driven computer interface

19. Alan Kay’s 1968 vision of how computing COULD be: The Dynabook

20. Alan Kay’s 1970’s XEROX PARC work
The Graphical User Interface GUI
But Xerox corporate didn’t think it was important

21. which opens the door for Steven Jobs
Macintosh 1984
…and personal computing as we know it is born