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1 Accessing the Global Database The World Wide Web.

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Presentation on theme: "1 Accessing the Global Database The World Wide Web."— Presentation transcript:

1 1 Accessing the Global Database The World Wide Web

2 2 u The Origin of the Internet (Past) u What is WWW ? (Present) u What Can We Expect (Future) Topics Outline

3 3 The Origin of the Internet u Where Did the Internet Come From? u What Is the Internet? u Who’s Who in WWW

4 4 Where Did the Internet Come From? u ARPANET of the 60s and 70s (DOD) u NSFNet (Scientific/Academic) u Internet (Global)

5 5 Network u LAN -- e.g., room, school u Over City -- e.g., school system u Within the US -- e.g., domestic company u Around the World -- e.g., international company

6 6 Local Area Network (LAN) u What – Group of computers that can communicate to one another within a limited area u Why – To share resources (files, printers, storage area – Intranet u Where – Within Room – Within Building – Within Campus

7 7 What Is The Internet? u a world-wide collection of networks u TCP/IP (Transmission Control Protocol/Internet Protocol) u Services u Internet Address

8 8 Internet Services u World Wide Web – network of Web servers holding hypertext pages u Telnet – remote computer access u FTP – file transfer between remote computers u E-mail – electronic correspondence u VOIP (Voice Over Internet Protocol) – Telephone over the Internet

9 9 About Address u IP Address – ( u E-mail Address – u URL – http:/ html

10 10 URL (uniform resource locator) 103sched.html ---- protocol --- server name -------------- domain --------------------- path ------------- file

11 11 What Is World Wide Web? u World Wide Web – System of servers that maintain specially formatted documents, which are hyperlinked to other documents and files. WWW uses the Internet to transmit such documents and files. u Internet – Collection of many networks in countries worldwide u Web Page – computer file which is publicly available, containing text, sound, graphics, and film clips – URL (universal resource locator) u Hypertext – data file embedded with links to other data sources

12 12 Growth of WWW u Internet – text-based commands u Hypertext + Internet --> WWW – to make scientific data available – at CERN, Switzerland (1991) u Graphic Browsers – Mosaic (1993) – Netscape – Internet Explorer

13 13 Search Engines u A program that searches documents for specified keywords and returns a list of the documents in the WWW where the keywords were foundprogramsearcheskeywords u List of Search Engines List of Search Engines u Natural Language Search Natural Language Search

14 14 Who’s Who in WWW? u Theodor Holm Nelson – invented hypertext u Tim Burners-Lee – created World Wide Web at CERN, using hypertext and Internet u Marc Andressen and Eric Bina – created Mosaic – Andressen created the Netscape browser u James Gosling – invented the Java language

15 15 New Internet Applications u Running Programs – using applets u Team Computing – developing documents and software u E-Commerce – Tele-Shopping – Banking -- security, privacy are concerns – Communications-- text + audio + video; “movies on demand” u Internet Phone

16 16 New Applications u Data distributed on the Web – no need for large local storage space u Programs loaded directly from Web sites – no machine dependency u “Net Computers” – PC designed specifically for Internet use; less storage but FAST connection; inexpensive u E-Commerce

17 17 Problems to be Solved u Security u Privacy u Communication Speed u Domain Names u Economic Haves and Have-nots u Technological literates and illiterates u Copyright Laws u Cyber Terrorism

18 18 Summary u Internet connects computers around the world u WWW is a subset of the Internet u WWW is a collection of Web servers housing hypertext “pages” u Pages are linked via the Internet u Networks will change the way computers are used u Problems of Security and Privacy must be solved u Copyright laws need to be updated

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