World Wide Web

The World Wide Web is an exciting area for discovery and innovation. It is built around the concept of hypertext. This involves linking one document to another document so that the second can explain a term or concept in the first. For instance, let's say you're reading a document on salmon, and you reach a section where the word "roe" is marked in some way to make it stand out from the rest of the text (usually underlined and/or in color). If you move your cursor to the word "roe" and click once (not twice as in operating systems!), you'll view a document which explains what roe are and may add some characteristic of salmon roe. Exciting, eh? It's a way of building in definitions and additional explanatory material without disrupting the flow of the text for those who may not need that material.

Many electronic encyclopedias have used this same concept, some with quite interesting audiovisual items in place of text explanations. This is the other exciting part of World Wide Web: the graphics and sound capabilities. You can link documents to images and pictures and sound clips for a more exciting package. Just click on the word "lion," for instance, and you'll hear it roar. Many folks who use World Wide Web home pages as business cards will have a photograph of themselves or the family included on the page. (see my home page for example). A home page is the first page or screen at a World Wide Web site.

Beyond the hypertext and audiovisuals, the World Wide Web is really a web of information and connections. Each item you choose in a Web site will either take you to another spot in the site you were in or will lead you to another part of the Web. You can always get back to where you were by retracing you steps.

What's In A Name?

Just to mention this so that you won't be confused later, the Web has a number of different acronyms and abbreviations. It can be referred to in any of the following ways:

World Wide Web (three syllables)

WWW (nine syllables)

W3 (four syllables)

the Web (two syllables)

Who Invented the WWW? (this section of the lesson was adapted from CERN's web site)

In late 1990, Tim Berners-Lee, a computer scientist at the European Laboratory for Particle Physics (CERN) invented the World Wide Web (that you are currently using). The "Web" as it is affectionately called, was originally conceived and developed for the large high-energy physics collaborations which have a demand for instantaneous information sharing between physicists working in different universities and institutes all over the world. Tim together with Robert Cailliau wrote the first WWW client (a browser-editor running under NeXTStep, a cousin of the Macintosh) and the first WWW server along with most of the communications software, defining URLs, HTTP and HTML.

The World-Wide Web was first developed as a tool for collaboration in the high energy physics community. From there it spread rapidly to other fields, and grew to its present impressive size. As an easy way to access information, it has been a great success. But there is another side to the Web, its potential as a tool for collaboration between people. Here is some background to the early development of the World-Wide Web, a brief overview of its present state and an introduction to the concepts on which it is based.

In spite of all this enthusiasm for electronic communication, there were many obstacles in the 1980s to the effective exchange of information. There was a great variety of computer and network systems, with hardly any common features. Users needed to understand many inconsistent and complicated systems. Different types of information had to be accessed in different ways, involving a big investment of effort by users. The result was frustration and inefficiency.

This was fertile soil for the invention of the World-Wide Web by Tim Berners-Lee. Using WWW, scientists could at last access information from any source in a consistent and simple way. The launching of this revolutionary idea was made possible by the widespread adoption of the Internet around that time. This provided a de facto standard for communication between computers, on which WWW could be built. It also brought into being a "virtual community" of enthusiastic computer and communications experts, whose attitude fostered progress via the exchange of information over the Internet.

The first proposal for such a system was made at CERN by Tim Berners-Lee in 1989, and further refined by him and Robert Cailliau in 1990. By the end of that year, prototype software for a basic system was already being demonstrated. To encourage the adoption of the system, it was essential to offer access to existing information without having to convert it to an unfamiliar format. This was done by providing an interface to the CERN Computer Centre's documentation and help service, and also to the familiar Usenet newsgroups. All this information immediately became accessible via a simple WWW browser, which could be run on any system.

The early system included this browser, along with an information server and a library implementing the essential functions for developers to build their own software. This was released in 1991 to the high energy physics community via the CERN program library (via FTP), so that a whole range of universities and research laboratories could start to use it. A little later it was made generally available via the Internet, especially to the community of people working on hypertext systems. By the beginning of 1993 there were around 50 known information servers.

At this stage, there were essentially only two kinds of browsers. One was the original development version, very sophisticated but only available on NeXT machines. The other was the "line-mode" browser, which was easy to install and run on any platform but limited in power and user-friendliness. It was clear that the small team at CERN could not do all the work needed to develop the system further, so Tim Berners-Lee launched a plea via the Internet for other developers to join in.

Early in 1993, the National Center for Supercomputing Applications (NCSA) at the University of Illinois released a first version of their Mosaic browser. This software ran in the X Window System environment, popular in the research community. It could thus offer friendly window-based interaction on a platform in widespread use. Shortly afterwards NCSA also released versions for the PC and Macintosh environments. By late 1993 there were over 500 known servers, and WWW accounted for 1% of Internet traffic, which seemed a lot in those days!

Tim Berners-Lee now works at the Laboratory of Computer Science at the Massachusetts Institute of Technology, MIT, where Berners-Lee has taken up a research appointment. By the way, he makes no royalties for his invention of the WWW!

Netscape vs. Mosaic vs. Internet Explorer: Ways to the Web

Netscape, Mosaic, and Explorer are all ways to get connected to the Web and to do some exploring. Basically, they're WWW browsing software that need to be in place on an Internet-connected computer so that Web sites and the computer can communicate.

Netscape, Mosaic and Explorer are similar to one another: they all allow you to see the wonderful images and hear the sounds out on the Web. They are also all "cousins" to one another--Mosaic was the first web browser. Its developer later left NCSA to form his own company--Netscape (more on this below). His earlier creation, Mosaic continued to be licensed to various entities and eventually Microsoft purchased one of these licenses. Their version of Mosaic came to be called Internet Explorer.

Netscape: The little company that grew

Netscape Communications was started by a Silicon Valley computer tycoon and a graduate student by the name of Marc Andreessen. Mr. Andreessen developed the first graphically-oriented WWW browser, NCSA Mosiac, while at the National Center for Supercomputer Applications (NCSA) at the University of Illinois at Urbana-Champaign. When he moved to California, he took Mosaic with him. With the help of Jim Clark's (his investor, the Silicon Vally tycoon) money and other programmers, Andreessen rewrote and enhanced Mosaic. His creation is called Netscape Navigator (the official name of the program, but most people just call it Netscape). Netscape's newest product, Netscape Communicator, takes Navigator several steps further with integrated email, conferencing, web page editing, etc.

Netscape requires System 7 to run on a Macintosh. It requires Windows 3.1 or Windows '95 and a graphics card to run on a PC. In either environment it is a memory-hog, typically needing a minimum of 12-24 megabytes of RAM (Random Access Memory) to run comfortably.

In 1994, everyone used NCSA Mosaic for their graphically-oriented Web browsing. Within a year, nearly 90% of Web browsers were using some form of Netscape. Netscape's mascot Mozilla (a friendly cartoon Godzilla), whom you'll see from time-to-time when you visit Netscape's Web pages, is now a common site for many Web users. Since 1997, Microsoft Internet Explorer has made dramatic inroads on Netscape's dominance.

When you start a web browser application such as Netscape, you will begin at that program's home page. Most often you will default to either Augsburg's WWW home page or Netscape's WWW home page (in California). This home page can be changed by the user. Both give you some interesting Internet starting points. A shortcut to these starting points (such as searching tools, what's new and cool, etc.) can be found on a bar across the top of the page just below the square navigation icons. These rectangular buttons can be clicked (remember, click only once!) to perform the indicated operations. These choices and a few more are also found under the Directory menu.

Much of the appeal of the WWW in general, and web browsers in particular, are their ease of use. If you want to go somewhere or find something, choose "Net Search" and you'll be provided with a variety of search tools (also called search engines, because they drive the search activity). The results of your plain English search is a clickable list. To go to any of the places on this list, just click on its title--it's that easy!

Web Addressing: the Miracle of HTTP (some of the following discussion was adapted from "Journey Beyond the Enter Key" an article in the Skyway News by Steven Dahnman).

Question: What happens when you type an Internet address (URL) into a browser? How does it find the Web page?

Answer: That is the first step in a long journey. When you type a URL into your web browser, you are initiating a very interesting set of events which occurs so fast and reliably that most computer users are completely unaware of the complex bit of engeneering they have just witnessed!

Let's take this made-up URL for example -- http://www.augsburg.edu:80/about/lib_infotech.html -- "http" stands for HyperText Transfer Protocol, which is a protocol (a set of rules governing a relationship) for formatting commands on the World Wide Web. Another common protocol is "ftp," used to transfer files.

The "www" refers, of course, to the World Wide Web, which is the universe of network-accessible information, also known as simply the "Web." (What's the difference between the Web and the Internet? The Internet came first and then the World Wide Web was developed in 1990 to navigate it. But you knew that already, right?)

Then we get to the domain name, a means for identification and location of computers on the Internet. Actually, computers use numbers -- called "Internet Protocol" addresses -- to find each other, such as 209.52.165.123. But since that's not as catchy as "www.augsburg.edu," there are databases that match domain names with IP addresses.

These databases are located on computers called "name servers." When you type in an URL, your browser sends a request to the nearest name server, which will return an IP address, if it knows what it is, or it will ask another name server if it recognizes the name. If that second server doesn't know, the second server will ask a third server, and so on and so on. Eventually, it will get to an "authoritative server," which either recognizes the address, or else it doesn't exist--leading to the dreaded "Error 404" message.

Once the computer has been located, it's time to request a particular file. The directory and file location would be specified with a slash to the right of the domain name, followed by a filename and extension. Each slash in the URL refers to a subdirectory or folder. So this example HTML home page (http://www.augsburg.edu:80/about/lib_infotech.html) resides in a folder called "about" on a computer named "www.augsburg.edu," and, by the way, look for "www.augsburg.edu" at port 80. These addresses can often get quite long, as documents are often placed in sub-sub-areas of subareas of areas at a particular site (no, I didn't mistype this last sentence 8-) ).

If there is no filename, the computer will send the default file, such as "index.html." This would tell your browser to display the file as an HTML document which, as you know, is a text file with HyperText Markup Language tags to display words and images in a specific format.

One recent innovation in web addressing is the shortcut. Netscape version 2.0 or newer and Internet Explorer will allow you to "shortcut" some web addresses if they follow a familiar pattern. This pattern--www.domain-name-here.com--is becoming so common that these browsers will assume the "www." and the ".com" parts of the address if you type-in just the name. For example, if you want to browse the Disney WWW site (http://www.disney.com) you can type "disney" and get there the same as if you typed the entire "http://www.disney.com." You can even shortcut web sites in subdirectories--e.g., when you need to go to "http://www.disney.com/mickey/" could type the shortcut "disney/mickey." Remember, this only works with Netscape version 2.0 or newer and Microsoft Internet Explorer, and only for web sites whose names follow this pattern.

More about URLs (pronounced "Earls")

The naming convention used to accomplish this trick is called a URL--Universal Resource Locator. URLs are the standard naming format for the Internet. They allow web browsers to take you to many different kinds of Internet resources. You can tell which kind of resource you're about to visit by looking at its URL (pronounced "Earl"). Here is a table of the most common URL prefixes:

Now don't immediately throw away NewsWatcher! Even though it is technically possible to read newsgroups using your web browser, remember that some computers cannot run fully featured web browsers, so these software tools are valuable for connecting these older machines to the Internet. Unfortunately, NewsWatcher cannot return the favor and link you to Web sites. Think of Netscape as the "Swiss Army knife" of the Internet. But just as when you want to do some serious cutting, you probably wouldn't use a Swiss Army knife--the same might be said of Netscape. If you want to do serious newsgroup work, NewsWatcher is a better tool.

Conclusion

Now that I've given you the ability to get hooked on a new area of the 'Net, be sure to feed your addiction with a steady flow of new sites. The Scout Report is a good resource. It also includes other 'Net tidbits, and is distributed about once a week. The Internet Scout Report's Web Page can be found at:

http://scout.wisc.edu/index.php

Enjoy that virtual world out there!

Internet Lessons version 1.8. Copyright of lessons (C) 2007 by Joseph A. Erickson, All Rights Reserved. Permission Granted for Individual Usage.

If you plan to distribute multiple copies of this work, please contact the author.

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