Transcript Internet
COSC1078 Introduction to Information Technology Lecture 19 Internet James Harland [email protected] Lecture 19: Internet Intro to IT Introduction to IT 1-4 Introduction, Images, Audio, Video 5-6 Computer Fundamentals Assignment 1, WebLearn Test 1 7 Review 8 Operating Systems WebLearn Test 2 9 Operating Systems Assignment 2 10 Survey & Internet 11 Internet Security WebLearn Test 3 12 Future of IT Assignment 3, Peer and Self Assessment Lecture 19: Internet Intro to IT Survey Who is this? Cecily Walker Teaching and Learning Advisor 10.10.1 [email protected] Lecture 19: Internet Intro to IT Overview Survey Questions? Assignment 3 Internet Questions? Lecture 19: Internet Intro to IT Assignment 3 Review (re-) answer What is IT? questions from Tutorial 1 Identify difficult parts of the course Suggest new questions Include favourites from Assignments 1 and 2 Reflect Answer reflection questions from tutorials Research Write about a particular IT topic of your choice (5-6 paragraphs) Lecture 19: Internet Intro to IT Internet Worldwide publically accessible network of (millions of) interconnected computer networks which carry information and provide services Lecture 19: Internet: Images Intro to IT Internet Lecture 19: Internet: Images Intro to IT Internet Lecture 19: Internet: Images Intro to IT Internet Lecture 19: Internet: Images Intro to IT Communications Developments ????: Writing 1440: Printing press 1844: Telegraph 1877: Telephone 1919: Radio 1928: Television 1969: ARPANET (Advanced Research Projects Agency) 1970's: Internet Protocol (IP) 1984: Domain names (.com, .org, etc) 1991: World Wide Web .... Lecture 19: Internet: Images Intro to IT Number of Internet Hosts 600000 500000 400000 300000 200000 100000 0 1991 1992 1993 1994 1995 1996 Lecture 19: Internet: Images 1997 1998 1999 2000 2001 2002 2003 2004 Intro to IT 2005 2006 2007 2008 Internet Originally designed to survive nuclear war Grew out of army research into missile communication Key role in breaking down the Berlin Wall Internet Dedicated channel: two nodes exclusively use a single channel works like traditional telephone Packet switching: break data down into packets send packets from many users along link can exploit redundancies and variations in network Lecture 5: Internet Intro to IT Protocols Transmission Control Protocol (TCP): basic necessities for data transfer connection-oriented Internet Protocol (IP): data-oriented necessary for packet-switched network “Should run on two tin cans and a string” There is an implementation for carrier pigeons ... Lecture 5: Internet Intro to IT Protocols Lecture 5: Internet Intro to IT Application Protocols Define messages sent and data formats used Generally known by user Examples include HTTP, HTTPS, FTP, etc. Often specified in resource identifiers http://www.mysite.com:8080/info/mypage.html http://www.mysite.com:8080/info/mypage.html http://www.mysite.com:8080/info/mypage.html http://www.mysite.com:8080/info/mypage.html Lecture 5: Internet Intro to IT World Wide Web (WWW) Combination of 4 different ideas: Hypertext: information format for moving documents around Markup Language: codes embedded in text indicating structure and presentation meaning Resource Identifiers (URI, URL, ...) Client-server model: client software requests resources from servers Lecture 5: Internet Intro to IT Internet Uses File transfer & remote services Email Instant messaging Web browsing Peer to peer (P2P) Telephony Streaming media “Web 2.0” .... Lecture 5: Internet Intro to IT Conclusion Work on Assignment 3 Name 5 people who are unaffected by the Internet … Lecture 19: Internet Intro to IT