1. Digital Media Dr. Jim Rowan ITEC 2110

2. The Internet your computer DHCP: your browser (Safari)(client) webpages and other stuff yahoo.com (server) 235.01.30.240 walmart.com (server) 100.43.153.07 Domain Name System (DNS)

3. yahoo.com (server) 235.01.30.240 The Internet walmart.com (server) 100.43.153.07 ISP DHCP: 135.10.34.222 your computer your browser (Safari)(client) webpages and other stuff Domain Name System (DNS)

4. yahoo.com (server) 235.01.30.240 The Internet walmart.com (server) 100.43.153.07 DHCP: 135.10.34.220 your computer your browser (Safari)(client) http://www.yahoo.com Domain Name System (DNS) http://www.yahoo.com = 235.01.30.240 webpages and other stuff

5. yahoo.com (server) 235.01.30.240 The Internet walmart.com (server) 100.43.153.07 /index.html DHCP: 135.10.34.222 your computer your browser (Safari)(client) http://www.yahoo.com Domain Name System (DNS) http://www.yahoo.com = 235.01.30.240 webpages and other stuff

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 email

7. Parts of the Uniform Resource Locator URL Three parts: –Specifies the protocol to use HTTP FTP SMTP –The Domain Name www.ggc.usg.edu –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. http://cgi.ebay.com/ ebaymotors/ws/eBayISAPI.dll ?ViewItem&item=260182066605& ssPageName=ADME:X:AAQ:MOTORS:1123 http://www.almanac.com/weatherhistory/oneday.php?number =747808&wban=99999&day=31&month=3&year=2008&sear chtype=zip http://www.google.com/ search?hl=en&q=tim+berners-lee&btnG=Google+Search Locating stuff on a server http://www.jimrowan.com/about/before1990/research.html http://www.jimrowan.com/about/after1990/hobbies.html

12. WebCrawlers Once looked and collected email addresses to sell to spammers Simple to do –request a page –look through the text of the page for something @ 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!”TCPDNS –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