The Internet and the World Wide Web • What is the Internet?
• World Wide Web
• Models of Communication
History of the Internet and the World Wide Web I nternet vs. i nternet An internet (small “i”) refers to any network of computers The Internet (large “I”) is a specific name Given to the communication network comprised of hundreds of thousands of inter-connected networks
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History of the Internet and the World Wide Web An intranet is a computer network that uses Internet Protocol technology to share information, operational systems, or computing services within an organization. The term is used in contrast to internet, a network between organizations, and instead refers to a network within an organization
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History of the Internet and the World Wide Web /cont./ During the Cold War in the 1960s, the U.S. Department of Defense Advanced Research Project Agency (ARPA) initiated a research project to create a network of geographically separated computers that could exchange information even if some of the nodes stopped functioning or were destroyed in the event of nuclear attack.
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History of the Internet and the World Wide Web /cont./ In 1969 this research successfully connected the main frames of four western universities- Stanford University, University of California, Santa Barbara, University of California, Los Angeles and Utah State University, leading to the invention of Internet
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History of the Internet and the World Wide Web /cont./ New computers were gradually added to the network including those of government agencies, universities and research institutes. 57 “nodes” in 1975 The networks of these agencies are interconnected, thus forming the “Internet” By the end of 1989, more than 100,000 computers were globally connected to the “Internet”
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History of the Internet and the World Wide Web /cont./ Internet surfing -- pre-browser era Before the Web, information retrieval was accomplished through a number of complicated steps and commands Difficult Time consuming Required greater-than-normal understanding of computing in order to operate
History of the Internet and the World Wide Web /cont./ In the 1980’s: Tim Berners-Lee of CERN (European Laboratory of Particle Physics) began working on WWW Software for world-wide interconnectivity Berners-Lee -- Father of WWW Developed the Web as a means of sharing scientific information in 1990 Invented HTTP (HyperText Transfer Protocol) HTML (HyperText Markup Language) URL(Universal Resource Locator)
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World Wide Web The World Wide Web is a system of interlinked hypertext documents and programs that can be accessed via the Internet primarily by using HTTP.
July 1995 Estimated 4 million documents available on the web
October 1995 Number had grown to 8.5 million pages
July 1996 Estimated to contain between 16 - 50 million pieces of information
January 2015 The Indexed Web contains at least 4.6 billion pages --http://www.worldwidewebsize.com/
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Models of Communication TCP/IP Sets definitions for how data transmission takes place. TCP (Transmission Control Protocols) Defines how computers communicate with each other
IP (Internet Protocols) Tells routers how to reassemble data packets
Models of Communication Several types of Internet Protocols: HTTP (Hypertext Transfer Protocol) WWW Documents
WAIS (Wide Area Info System Protocol) Rules for accessing text-only file indices
FTP (File Transfer Protocol) Data transfer from one computer to another
Telnet (Terminal Emulation Protocol) Used when logging into another system
Models of Communication Several types of Internet Protocols: SMTP (Simple Mail Transfer Protocol) Email
IRC (Internet Relay Chat) Chatting
IM (Instant Messaging) Instant Messaging Service
