Websites

The Web and

Websites

Along came a Spider!

2First: What is the Internet?

For one thing, it’s not really “the net”, it’s the “nets”:– “the Internet: a cooperatively-run

collection of computer networks that span the globe.”

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3Is it the same as the Web?

Internet ≠ World Wide Web– The Internet is a massive network of

networks, a networking infrastructure. – The World Wide Web, or simply Web, is a

way of accessing information over the medium of the Internet. It is an information-sharing model that is built on top of the Internet.

– The Internet, not the Web, is also used for e-mail, which relies on SMTP, Usenet news groups, instant messaging and FTP.• The Difference Between the Internet and the

World Wide Web

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4Cold 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

5Before 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

6Phone-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 world's 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

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7From 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”?

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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)

9When 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

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1975, the net goes commercial

Telenet– 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

11Telenet is not to be confused with Telnet

What is telnet? – Telnet and its close

cousins rlogin and tn3270 are methods of connecting to a remote [mainframe] computer over the Internet that let you use programs and data just as if you were using the computer locally. Do not confuse telnet with Telenet, the old name for Sprintnet.

– Telnet is a text-only protocol. At one time it was one of the most common ways to connect to other sites.• Telnet FAQ © 2001 Walt Howe

(last updated 30 April 2001)

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Significance of Telenet?

Published 1991

131980s

Main uses scholarly or military– Libraries use networks like Telenet and

Tymnet for remote searching of databases– Scientists and scholars communicate by email

The Silent 700 was a line of portable computer terminals manufactured by Texas Instruments in the 1970s and 1980s. Silent 700s printed with a dot-matrix heating element onto a roll of heat-sensitive paper. They were equipped with an integrated acoustic coupler and modem that could receive data at 30 characters per second.

14What, no fun things?

Enter the BBS!– Bulletin Board System

• A Bulletin Board System, or BBS, is a computer system running software that allows users to connect and log in to the system using a terminal program. Once logged in, a user can perform functions such as uploading and downloading software and data, reading news and bulletins, and exchanging messages with other users, either through electronic mail or in public message boards. Many BBSes also offer on-line games, in which users can compete with each other, and BBSes with multiple phone lines often provide chat rooms, allowing users to interact with each other.

15BBS all text, very little graphics

Monochrome BBS, known to users as “Mono”, was originally a student bulletin board system at [London’s] City University in the early 1990s. The BBS is still

in existence with a web presence at http://www.mono.org/ from where you can connect to the real thing by telnet. See also Monochrome BBS – Definition.

16Related to BBS

Gopher – 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)

17A Gopher menu

From a Finnish History of the Internet (click on 1991 to get the page where this is reproduced)To navigate the menus, you used the arrow keys (no mouse, of course!) to move the arrow up or down the menu and then hit Enter to select the item you want. Current browsers no longer support Gopher.

18Veronica, Jughead and Archie (but not Betty)!

Rodent companions!– 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

19Finally, The Web is added: 1991

Tim 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

He almost called it the “Mesh”!

Sir Tim Berners-Lee on the Web (past, present and future)

20The first “real” browser

NCSA MosaicNCSA's Mosaic™ wasn't the first Web browser. But it was the first to make a major splash. In November 1993, Mosaic v 1.0 broke away from the small pack of existing browsers by including features—like icons, bookmarks, a more attractive interface, and pictures—that made the software easy to use and appealing to “non-geeks.”

About NCSA Mosaic

21Today’s browsers

22Alphabet soup of the Web

URL– Uniform Resource Locator

HTTP– HyperText Transfer Protocol

HTML– Hypertext Markup Language– Now being complemented by

XML• EXtensible Markup Language

– See What is XML?

23What does HTML or XML look like?

24A free site to create your own

What is Weebly?– Weebly is a San Francisco,

California based company that was founded in 2006 with the mission to help people put their information online quickly and easily. We now enable 3 million people to easily create personal sites and blogs or establish web presences for businesses, weddings, classrooms, churches, artistic portfolios, and more. •

25Basic URL Structure

Parts– 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.

26Domain 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

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Structure of a Domain Name 1

What is a Top Level Domain (TLD)?– A Top Level Domain (TLD) is the “suffix”

or the end of each domain name. (e.g., the “.com” in yahoo.com is the TLD.) There are two types of TLDs - global and country code.

Generic Top Level Domain (gTLDs) extensions include: .com, .net, .org, .biz, .coop, .edu, .gov, .info, .int, .mil, and .museum.

28Country code TLDs

– Country Code Top Level Domains (ccTLDs) are TLDs created by a country, such as .it, which is the country code for Italy or .tv which is the country code for Tuvalu, and of course .us for the United States • A complete list of ccTLDs (sorted by

ccTLD) can be found at http://www.iana.org/cctld/cctld-whois.htm.

oWhat is a Top Level Domain (TLD)?

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Structure of a Domain Name 2

Second-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.

30Structure of a Domain Name 3

SubDomain - 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

31Success 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 kid's 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 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.[1]

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

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