Agenda The Internet and the WWW what’s the difference anyway? History of The Internet IP Addresses, URLs & Domain Names READ Zeid: page 3-20

The Internet vs. World Wide Web What EXACTLY is the difference between the Internet and the World Wide Web? Why is it important to know the difference?

The Internet Computers can be connected in a variety of different ways. Ethernet, Token-ring, Wireless, Ports (Serial, Parallel, USB). These are all communication subtrates. Two or more connected computers form a Network The CS Dept. has its own Ethernet Network Different types of networks can be connected via bridges, gateways, etc.

The Internet Two or more connected networks can be called an inter-network Inter-networks can obviously be connected At some point in history, inter-networks became connected across the entire USA Eventually, inter-networks became connected across the entire world The entire world-wide collection of connected networks became known as The Internet.

The Internet Most experts in the “Network World” think of The Internet as both The physical infrastructure (wires, routers, hubs, switches, satellites, optical cables, receivers, transmitters, etc.) that form the inter- connections. And, the actual collection of computers (and devices) that are “inter-connected.”

The World Wide Web (WWW) Most experts think of The WWW as data that is accessible via a URL (narrow definition) All the data and services that are widely available via The Internet (general definition)

The World Wide Web (WWW) Thus, The Internet is the physical hardware that makes the connections possible and The World Wide Web is the content and services that are widely available over this massive collection of connected computers. Important Note: Some companies use the Internet to share information, but this information is only accessible through proprietary protocols, Since, it is NOT widely available, it is not really part of the WWW.

The World Wide Web (WWW) While the two terms are somewhat synonymous to the non-expert, You should be aware of the difference between The Internet and the WWW Internet WWW

Internet Jargon In the field of Network Communications there are thousands of terms, most of which are acronyms and are not found in standard dictionaries. The following website is good for reference:

The World Wide Web (WWW) Examples: Content & High-level Protocols Content: WebPages Hypertext Transfer Protocol (http) URL (Universal Resource Locator) Content: Data Files & Programs File Transfer Protocol (ftp) Content: Music & Videos Gnutella Protocol

The World Wide Web (WWW) More examples Content: SMTP (Simple Mail Transport Protocol) IMAP (Internet Message Access Protocol) POP (Post-Office Protocol) DNS (Domain Name System) MIME (Multipurpose Internet Mail Extensions) Content: Peer to Peer messaging AOL IM Protocol MSN Messenger Protocol

The Internet Examples: Hardware & Low-Level Protocols Hardware Computer, Ethernet card Communication Substrate: CAT-5 cable, fiber optic cable Router, Hub, Switch, Bridge, Gateway Low-Level Protocols/ Concepts TCP/IP (Transmission Control Protocol/Internet Protocol) Packet Switching

What is the Internet? The largest network of networks in the world. Uses TCP/IP protocols and packet switching. Runs on any communication substrate.

Brief History of the Internet DARPA (Defense Advanced Research Projects Agency) contracts with BBN (Bolt, Beranek & Newman) to create ARPAnet (Advanced Research Projects Agency) First five nodes: UCLA Stanford UC Santa Barbara U of Utah, and BBN

Brief History of the Internet TCP protocol invented by Vint Cerf 1984 – On January 1, the Internet with its 1000 hosts converts en masse to using TCP/IP for its messaging 1968 is really the “birth” of the Internet 1984 is really the “high-school graduation” of the Internet

WWW Created 1989 Mosaic Created 1993 Packet Switching Invented 1964 First Vast Computer Network Envisioned 1962 ARPANET is Born 1968 TCP/IP Created 1972 Internet Named TCP/IP Used 1984 Hypertext Invented 1965 Age of eCommerce Begins 1995

We can access information using electronic computers We do it reliably with “bits”, sending and receiving data We can do it cheaply by using Digital circuits etched in silicon. Great things can be done with a vast world-wide network We will prove that packet switching works over a WAN. Packet switching can be used to send digitized data though computer networks Hypertext can be used to allow rapid access to text data 1962

Ideas from 1940s to 1968 We need a protocol for Efficient and Reliable transmission of Packets over a WAN: TCP/IP The ARPANET needs to convert to a standard protocol and be renamed to The Internet Computers connected via the Internet can be used more easily if hypertext links are enabled using HTML and URLs: it’s called World Wide Web The World Wide Web is easier to use if we have a browser that To browser web pages, running in a graphical user interface context. Great efficiencies can be accomplished if we use The Internet and the World Wide Web to conduct business.

Claude Shannon The Father of Modern Information Theory Created the idea that all information could be represented using 1s and 0s. Called these fundamental units BITS. Won a Nobel prize for his master’s thesis in 1936 Source:

Vannevar Bush Summary: Vannevar Bush established the U.S. military/university research partnership that later developed the ARPANET. He also wrote the first visionary description of the potential use for information technology, inspiring many of the Internet's creators. Source: Livinginternet.com

Paul Baran Paul Baran developed the field of packet switching networks Worked for RAND organization (first think tank) Baran's architecture was well designed to survive a nuclear conflict, and helped to convince the US Military that wide area digital computer networks were a promising technology. Source: Livinginternet.com

Leonard Kleinrock One of the pioneers of digital network communications Helped build the early ARPANET.

Vinton Cerf Summary: Vinton Cerf is co- designer (with Bob Kahn) of the TCP/IP networking protocol. Worked for DARPA, projects include d the Packet Radio Net (PRNET), and the Packet Satellite Network (SATNET). Source: Livinginternet.com

Tim Berners-Lee The inventor of HTML. Now works for Laboratory for Computer Science (LCS)at the Massachusetts Institute of Technology (MIT). Directs the W3 Consortium, an open forum of companies and organizations with the mission to realize the full potential of the Web. Source: w3c.org

Internet Growth Trends 1977: 111 hosts on Internet 1981: 213 hosts 1983: 562 hosts 1984: 1,000 hosts 1986: 5,000 hosts 1987: 10,000 hosts 1989: 100,000 hosts 1992: 1,000,000 hosts 2001: 150 – 175 million hosts 2002: over 200 million hosts By 2010, about 80% of the planet will be on the Internet

Important Milestones September 2002 Netsizer.com – from Telcordia

The Internet was not known as "The Internet" until January 1984, at which time there were 1000 hosts that were all converted over to using TCP/IP. Chart by William F. Slater, III Sept. 1, 2002 Dot-Com Bust Begins

Internet’s Growth To get a market of 50 Million People Participating: Radio took 38 years TV took 13 years Once it was open to the General Public, The Internet made it to the 50 million person audience mark in just 4 years!

URLs Universal Resource Locator Human-readable WWW Address

IP Address Numeric Internet Address Part of the TCP/IP Protocol URLs are translated into IP Addresses by DNS Servers DNS Domain Name System