Internet to web: The 40-year old Internet and the 20-year-old Web
EDU626 Integrating Educational Technology Summer 2012 The Links that Became a WebThe 40-year Old Internet and the 20-Year Old Web
2First: What is the Internet?For one thing, it‟s not really “the net”, it‟s the “nets”: – The internet is “a cooperatively-run collection of computer networks that span the globe.”
A formal definitionInternet – The high-speed fiber-optic network of networks that uses TCP/IP protocols to interconnect computer networks around the world, enabling users to communicate via e-mail, transfer data and program files via FTP, find information on the World Wide Web, and access remote computer systems such as online catalogs and electronic databases easily and effortlessly, using an innovative technique called packet switching. The Internet began in 1969 as ARPAnet, a project of the U.S. Department of Defense.
Cold War Technology? Originally designed by the U.S. Department of Defense so that a communication signal could withstand nuclear war and serve military institutions worldwide, the Internet was first known as the ARPANet, the most robust communication technology. It is a system of linked computer networks, international in scope, that facilitates data transfer and communication services, such as remote login, file transfer (FTP), electronic mail (e-mail), newsgroups, and the World Wide Web. The Internet greatly extends the reach of each connected computer network (see: network effect, IP). – Internet
Before ARPANet Before ARPANET, most computer systems consisted of a massive computer -- sometimes the size of an entire room -- with user terminals hardwired to it. A terminal was some form of user interface, often consisting of a keyboard or punch card reader. Multiple users could access the computer simultaneously, in a technique called timesharing. Other early networks required a direct connection between host computers, meaning that there was only one path for information to flow through. The direct connections limited the size of these computer networks, which became known as local area networks (LANs). – How ARPANET Works
Phone-linked networks“In the 1960s, as many as a few hundred users could have accounts on a single large computer using terminals, and exchange messages and files between them. But each of those little communities was an island, isolated from others. By reliably connecting different kinds of computers to each other, the ARPANET took a crucial step toward the online world that links nearly a third of the worlds population today.” – Marc Weber, founding curator of the Computer History Museum’s Internet History Program On October 29, 2009, SRI celebrated the 40th anniversary of the first ARPANET connection.
From mainframes to minicomputers Before ARPANET, most computer systems consisted of a massive computer -- sometimes the size of an entire room -- with user terminals hardwired to it. What is a mainframe computer?
Minicomputers? Minicomputers are a largely obsolete class of multi-user computers which made up the middle range of the computing spectrum, in between the largest multi-user systems (mainframe computers) and the smallest single-user systems (microcomputers or personal computers). From Blog “Health Care Renewal”: [a] picture from the George Washington High School (Phila., PA) 1973 yearbook in front of [their] high schools DEC PDP-8/S:
When did ARPAnet become the Internet? “. . . Ray Tomlinson is credited with inventing email in 1972. . . . He picked the @ symbol from the computer keyboard to denote sending messages from one computer to another. So then, for anyone using Internet standards, it was simply a matter of nominating name-of-the- user@name-of-the-computer. “. . . 1975 seems to be the definitive year in which, for the first time, networks connected to each other.” – Ian Peter’s History of the Internet
1975, the net goes commercialTelenet – One of the first value-added, packet switching networks that enabled terminals and computers to exchange data. Established in 1975 by Dr. Lawrence Roberts, who helped to develop ARPANET, Telenet was acquired by GTE in 1979. After it was acquired by Sprint in 1986, it was renamed SprintNet
Packet switching?Almost like USPS delivery – In a packet-switched network, no circuit is set up prior to sending data between devices. Blocks of data, even from the same file or communication, may take any number of paths as it journeys from one device to another. Compare this to Figure 1 [circuit switching is essentially a direct connection]
1980s Main uses scholarly or military – Libraries use Telenet and Tymnet for remote searching of databases – Scientists and scholars communicate by emailThe Silent 700 was a line of portablecomputer terminals manufactured by TexasInstruments in the 1970s and 1980s. Silent700s printed with a dot-matrix heatingelement onto a roll of heat-sensitive paper.They were equipped with an integratedacoustic coupler and modem that couldreceive data at 30 characters per second.
What, no fun things?Enter the BBS!– Bulletin Board System – A forum for users to browse and exchange information. Computer BBSs are accessible by telephone via a personal computer and a modem. Many BBSs are small operations run by a single person that allow only several users to log on at the same time. Some are much larger and allow hundreds of users to login simultaneously to use the system. Huge, commercial examples are America Online, CompuServe, and Prodigy. • From Glossary of Distance Education and Internet Terminology
Related to BBSGopher – The Gopher Protocol is a distributed document search and retrieval protocol that was developed at the University of Minnesota in the late 1980s. Resources are stored on Gopher servers, which organize information using a hierarchical directory structure. Gopher clients access servers to retrieve directory listings of available resources, which are presented to the user as a menu from which an item may be selected for retrieval. • Gopher Protocol (Gopher) (Page 4 of 4)
A Gopher menuHong Kong Baptist University’s Home Gopher MenuTo navigate the menus, you used the arrow keys (no mouse, of course!) tomove the arrow up or down the menu and then hit Enter to select the itemyou wanted. Current browsers no longer support Gopher.
Veronica, Jughead and Archie!Rodent companions (note: no Betty)! – Veronica: “Very Easy Rodent-Oriented Net- wide Index to Computerized Archives” – Jughead: “Jonzy’s Universal Gopher Hierarchy Excavation and Display” – Archie: a popular FTP [“File Transfer Protocol”] search program of the time. Though the legend of Archie being named for the cartoon, the name in fact is shorthand for “Archives.” • A Pre-Web Search Engine, Gopher Turns Ten By Chris Sherman, Search Engine Watch, Feb 6, 2002
The Web is added: 1991Tim Berners-Lee: – “. . . in 1989, while working at the European Particle Physics Laboratory, I proposed that a global hypertext space be created in which any network- accessible information could be refered to by a single “Universal Document Identifier”. Given the go-ahead to experiment by my boss, Mike Sendall, I wrote in 1990 a program called “WorldWideWeb”, a point and click hypertext editor which ran on the “NeXT” machine. This, together with the first Web server, I released to the High Energy Physics community at first, and to the hypertext and NeXT communities in the summer of 1991.” • The World Wide Web: A very short personal history
The first “real” browserNCSA Mosaic In 1991, the NCSA introduced NCSA Mosaic, the first readily-available graphical Web Browser that virtually kickstarted the dot.com revolution. It may not look like much now - but it is interesting to consider how similar modern browsers look to the original. PawPrint.net Glossary of Terms
Alphabet soup of the WebURL – Uniform Resource LocatorHTTP – HyperText Transfer ProtocolHTML – Hypertext Markup Language – Now being complemented by XML • EXtensible Markup Language – See What is XML?
Basic URL StructureParts – A URL has three basic parts: the protocol (how to get the resource); the server id (who to get the resource from); and the resource id (the name of the resource and how to find it on the target machine). In its most basic form, this looks like the following: – The "http" indicates that this is a Web document. The "www.fake.com" is the domain name of the (in this case, fictional) machine on which the web server is running (we know it’s a web server because of the protocol). And, of course, “doc.html” is the filename of the HTML document (notice the file extension “.html”) on that machine.
Other url address typesGopher URLs – gopher://gumby.brain.headache.edu:151/7fonebook.txt Access the searchable index “fonebook.txt” from the named gopher server, running on port number 151. [It’s unlikely that you will be access this: few modern browsers support gopher any longer ]Mailto URL – mailto:user@host?subject=Happy%20lobsters [Allows you to] include mail headers within the mailto URL. [This] example [will] send a letter with the subject line “Happy lobsters”. • For other examples, see Uniform Resource Locators (URLs) from Introduction to HTML by Ian Graham, The Information Commons, University of Toronto. Last Update: 20 September 2000
Domain name?What is a „Domain Name‟? – Domain Name System, or DNS, is the most recognized system for assigning addresses to Internet web servers (aka “Internet hosts”). Somewhat like international phone numbers, the domain name system helps to give every Internet server a memorable and easy-to- spell address. Simultaneously, the domain names keep the really technical IP address invisible for most viewers. • By Paul Gil, About.com Guide
Structure of a Domain Name 1Top-level domain or first-level domain – Every domain name has a suffix that indicates the Top Level Domain (TLD) to which it belongs. The TLD is the part of an internet domain name which can be found to the right of the last point. Generic TLDs include .com, .int, .net, .info, .org, etc. There are also many country code top level domains (ccTLDs) such as .es, .it, .cz and .be. Each TLD is associated with a particular registry which registers the names associated with the TLD. • What is a Top Level Domain (TLD)? • The .eu Top Level Domain
Structure of a Domain Name 2Second-level domain – In the Domain Name System (DNS) hierarchy, it is the highest level underneath the top-level domains. It is that portion of the domain name that appears immediately to the left of the top-level domain, separated by a dot. For example, the “NetLingo” in www.netlingo.com is a second-level domain.
Structure of a Domain Name 3SubDomain - The Third Level Domain – If you need to further distinguish your second-level domain name, you can use a third-level domain name, such as “resources.hostway.com.” Typically a third-level domain name is used to refer to different servers within different departments of a company. • Creating third-level domains
Success of the web?Tim Berners-Lee: – The success of the World Wide Web, itself built on the open Internet, has depended on three critical factors: 1) unlimited links from any part of the Web to any other; 2) open technical standards as the basis for continued growth of innovation applications; and 3) separation of network layers, enabling independent innovation for network transport, routing and information applications. Today these characteristics of the Web are easily overlooked as obvious, self-maintaining, or just unimportant. All who use the Web to publish or access information take it for granted that any Web page on the planet will be accessible to anyone who has an Internet connection, regardless whether it is over a dialup modem or a high speed multi-megabit per second digital access line. The last decade has seen so many new ecommerce startups, some of which have formed the foundations of the new economy, that we now expect that the next blockbuster Web site or the new homepage for your kids local soccer team will just appear on the Web without any difficulty. • Testimony of Sir Timothy Berners-Lee, Hearing on the “Digital Future of the United States: Part I -- The Future of the World Wide Web”
The internet a conversation? The Internet is a far more speech-enhancing medium than print, the village green, or the mails. . . . The Internet may fairly be regarded as a never-ending worldwide conversation. Statement by a federal judge in American Civil Liberties Union v. Reno, 929 F. Supp. 824, 844 (E.D. Pa. 1996) (Dalzell, J.). Quoted by Tim Berners-Lee in his Testimony at Hearing on the “Digital Future of the United States: Part I -- The Future of the World Wide Web”