Скачать презентацию Digital Media Dr Jim Rowan ITEC 2110 Скачать презентацию Digital Media Dr Jim Rowan ITEC 2110

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Digital Media Dr. Jim Rowan ITEC 2110 Digital Media Dr. Jim Rowan ITEC 2110

your browser (Safari)(client) DHCP: your computer webpages and other stuff yahoo. com (server) 235. your browser (Safari)(client) DHCP: your computer webpages and other stuff yahoo. com (server) 235. 01. 30. 564 walmart. com (server) 100. 43. 153. 07 The Internet Data Name System (DNS)

your browser (Safari)(client) DHCP: 135. 10. 34. 443 your computer ISP webpages and other your browser (Safari)(client) DHCP: 135. 10. 34. 443 your computer ISP webpages and other stuff yahoo. com (server) 235. 01. 30. 564 walmart. com (server) 100. 43. 153. 07 The Internet Data Name System (DNS)

your browser (Safari)(client) http: //www. yahoo. com DHCP: 135. 10. 34. 443 your computer your browser (Safari)(client) http: //www. yahoo. com DHCP: 135. 10. 34. 443 your computer webpages and other stuff yahoo. com (server) 235. 01. 30. 564 walmart. com (server) 100. 43. 153. 07 The Internet Data Name System (DNS) http: //www. yahoo. com = 235. 01. 30. 564

your browser /index. html (Safari)(client) http: //www. yahoo. com DHCP: 135. 10. 34. 443 your browser /index. html (Safari)(client) http: //www. yahoo. com DHCP: 135. 10. 34. 443 your computer webpages and other stuff yahoo. com (server) 235. 01. 30. 564 walmart. com (server) 100. 43. 153. 07 The Internet Data Name System (DNS) http: //www. yahoo. com = 235. 01. 30. 564

Web Protocols • Protocols define the rules to be followed in a conversation – 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

 • Parts of the Uniform Resource Locator URL Three parts: – Specifies the • 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

How to start your own website • You have to buy a Domain Name 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

…or to start a website • You could have your own server – Macs …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

…suppose on your Server: …suppose on your Server:

Locating stuff on a server http: //www. jimrowan. com/about/before 1990/research. html http: //www. jimrowan. Locating stuff on a server http: //www. jimrowan. com/about/before 1990/research. html http: //www. jimrowan. com/about/after 1990/hobbies. html http: //www. google. com/ search? hl=en&q=tim+berners-lee&btn. G=Google+Search http: //cgi. ebay. com/ ebaymotors/ws/e. Bay. ISAPI. dll ? View. Item&item=260182066605& ss. Page. Name=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

Web. Crawlers • Once looked and collected email addresses to sell to spammers • Web. Crawlers • 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 • Can be defeated by using unfriendly-to-robotcode like: jrowan (at) GGC (dot) USG (dot) EDU – humans can read this just fine!

Search Engines • Web crawlers look through the web looking for keywords • Then 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

And now for a little history. . . And now for a little history. . .

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

A brief history • Tim Berners-Lee – – invented the World Wide Web 1980 A brief history • Tim Berners-Lee – – invented the World Wide Web 1980 built the first web server mid 1980 s 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)

And now… Alan Kay And now… Alan Kay

 • Before Alan Kay • Command driven computer interface • Before Alan Kay • Command driven computer interface

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

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

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