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Introduction to the Internet. Present by: Selvakumar (Tech Lead, Senior Software Engineer, at ADT) & Part time Lecturer at Info Tech Sys Email: anselva@yahoo.com Web: www.nselva.com. Interconnected. …by CABLES OR Wireless. Definition. What is Internet?
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Introduction to the Internet Present by: Selvakumar(Tech Lead, Senior Software Engineer, at ADT) & Part time Lecturer at Info Tech Sys Email: anselva@yahoo.com Web: www.nselva.com
Interconnected • …by CABLES OR Wireless Definition What is Internet? Global Connection of Computer Networks
GSM Global System for Mobile communications (GSM)
Internet Services Chat E-Commerce Direct Communication E-Mail Newsgroups Online Conferencing Mailing-List Discussions WWW Distributed Information Resources FTP File Transfer
History About 40 Years Ago Advanced Research Projects Agency
Basic concepts Basic concepts: IP (Internet Protocol) – Number to identify computers DNS (Domain Name Server) – maintains a relationship between IP addresses and domain names ICANN (Internet Corporation for Assigned Names and Numbers) Register domain name eg: www.register.com
Terminology ISP (Internet Service Provider) Ex: SLT, Suntel, Dialog, Airtel, …etc
Internet Connection Phone Modem or Router Your PC ISP SLT, Lanka bell, Eureka, etc Internet
Connecting • Dial-up Connection–needs MODEM, Phone line and ISP account] • ISDN - (Integrated Services Digital Network) - Digital telephony scheme that allows a user to connect to the Internet over standard phone lines at speeds higher than a 56K modem allows
Connecting • ADSL - (Asymmetric Digital Subscriber Line) is a technology for transmitting digital information at high bandwidths on existing phone lines. • Unlike regular dialup phone service, ADSL provides a continuously-available connection.
Connecting • Cable Internet - Uses a cable modem designed to operate over cable TV lines. • Because the coaxial cable used by cable TV provides much greater bandwidth than telephone lines, a cable modem can be used to achieve extremely fast access to the World Wide Web.
How websites are working? IP: 74.220.215.243 Your Machine Who is look-up? ISP – Internet Service Provider DNS: www.nselva.com
Browsers • Web Browser
Terminology Web Page VS Web Site Any Ideas???
Terminology • HTTP = Hypertext Transfer Protocol • HTML = Hypertext Mark-up Language
HTML: Sample <html> <head> <title>Example</title> </head> <body> <p><font face="Arial"><br> <font color="#FF0000">Click here to see my pictures:</font></p> <p><a href="http://www.mysite.com/photos.html">My photograhps</a></p> </body> </html>
How can build a web site? • Register Domain Name • Hosting • Website design and development
URL: Sample Universal Resource Locator File Path Internet Protocol www.um.edu.mt/ faculties.html http:// Domain Name
Domains .com .gov .lk .org .net .co.uk .edu Etc…
Hosting After one creates a web-page or site one needs to upload it onto the internet. Example of Free hosting: www.freeservers.com www.fortunecity.com Otherwise one needs to pay for professional hosting services. ISP’s may offer this service.
XML XML - eXtensible Markup Language XML is not a replacement for HTML. In most web applications, XML is used to transport data, while HTML is used to format and display the data. <note><to>Siva</to><from>Karan</from><heading>Reminder</heading><body>Don't forget me this weekend!</body></note>
Useful Websites www.nselva.com - My personal website www.sevanthi.com - Download MP3 Songs www.kumbam.com - Matrimonial www.uoctamil.com - Colombo University Tamil Students www.x-rates.com - Exchange Rates www.cse.lk - Colombo Stock Exchange www.mathagal.com - Our Village www.cricinfo.com - Cricket Information http://kerni.jaffnahindu.org - Jaffna Hindu College Old boys