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The internet is a collection of interconnected computer networks that covers the entire globe. What we now know as the "Information superhighway" started as a US Department of Defense project. Today it can be accessed by anyone with a computer and a modem. Like the Internet itself, the World Wide Web started as a government funded project for scientists and academics to use to exchange information. What makes the World Wide Web special is its combination of Hypertext and Multimedia capabilities. Interest in the World Wide Web has mushroomed over the last couple of years and has caught practically everyone's attention.
The World Wide Web, as it is known today, began as a concept at a physics research center in Switzerland in 1989. Tim Berners-Lee of Geneva's European Particle Physics Laboratory (CERN) circulated a proposal to develop a "hypertext system" for the purpose of enabling efficient and easy exchange of information throughout the global physics community. The proposal contained three main goals:
By March of 1991, after two years of growing pains, the line-mode browser saw its first limited network use. In May of the same year the WWW was made more available at CERN. At the end of 1991 CERN announced the Web to the High Energy Physics community in general.
It was not until 1992 that CERN presented the Web to other audiences. The Web practically exploded onto the market. In January of 1993, 50 Web servers were in existence. That number increased tenfold to about 500 by October of the same year.
Today there are thousands of Web servers (computers that store and transmit Web documents) all over the world. These Web servers provide access to millions of World Wide Web hypertext pages today and the number is growing as you read this. Conservative estimates predict an annual growth rate of 3000% per year.
The growing popularity of the World Wide Web can be attributed in large to the ease with which information can be accessed.
A Web page is a document with links to other pages through hypertext links. Web pages can contain almost anything that you would expect to find in any printed document including text, tables and graphics.
Hypertext refers to electronic documents that contain "links" to other documents in a nonlinear fashion. Most books are written and read in a linear way, meaning that the reader starts at the beginning and reads page after page in an ordered fashion until the end. Hypertext is like a book with footnotes. You see a reference to a footnote in the main text (maybe for a definition of a word) and you go to the footnote and then back to the main text again. Hypertext allows the Web reader to jump from place to place within a document or even to other documents by clicking on "highlighted" words or phrases within the text. This jumping from place to place in a "no beginning and no end" structure describes a web, hence the name World Wide Web.
HTML stands for HyperText Markup Language. This is a standard set of codes or "tags" that are inserted into a document that is to be displayed as hypertext on the World Wide Web. These tags determine the structure of the document. They define how text and other components, such as graphics, are to be displayed. If you would like to see the "tags" of this page, click on the "view" button of your browser and choose the 'view source' option. This will display the source code of the page you are looking at. You will easily notice the tags as they are enclosed in 'greater than' and 'less than' signs (< >). These tags allow any browser running on any platform to display the page in much the same manner. With each improvement or addition to the HTML standard, new tags are created, and consequentially browser developers have to enable their browsers to recognize the new tags. To enhance web pages with animation, sound, video and even 3D, browser developers have allowed for the use of 'plug-ins'. These are helper applications that the browser will call when it sees a file with a particular extention. The plug-in will then run the file (perhaps a video clip) within the page. The use of these plug-ins has allowed web site developers to be much more creative and imaginative with their pages. More information on HTML.
A home page is similar to a table of contents in a book. It is the starting point or page that displays when you first access a site. It will introduce the author or company whose page it is and provide you with links to other pages (either by the same author or company at that site, or outside links to someone else's page at another site). It is sometimes explained by comparing it to a root directory in DOS with links to its subdirectories and also to other different directories. Home pages can contain anywhere from a few to a few hundred links to other pages.
Uniform Resource Locator. This is the addressing system used by the World Wide Web. It describes the location of a file or server anywhere on the internet. A typical URL will usually look something like this: "protocol://domain name/path and filename" (for example, this page's URL is http://64.220.92.229/beginners.htm) It has three separate parts:
For more information on URL's, follow this link.
On the Internet there are many protocols. These are the 'rules and regulations' that help to maintain the ease with which computers 'talk' to each other. The protocol part of the URL is essential in finding what you are looking for. It is the first part of the URL and it defines the type of server the selected link leads to. There are a few important ones to remember.
Type of Protocol Definition of Service
file:
In addition to referencing information located on the Internet,
most WWW browsers can also access files located on your hard drive. If file: is
followed by a ///C|, this indicates that the URL points to a file on your C: drive.
Otherwise it performs the same function as the ftp: protocol.
ftp:
FTP stands for File Transfer Protocol. If the nominated link
points to a file stored on an anonymous FTP server, the URL must begin with this
definition.
http:
Most HTML documents are stored on a WWW server. HTTP (hypertext
transfer protocol) refers to the protocol used by these servers (see
below).
gopher:
All WWW browsers can also navigate their way around a Gopher
server by using this protocol definition. Gopher is a service that enables the user to
navigate through Internet information easily. There are more than 1,000 gopher servers on
the Internet and Gopher client software is very easy to find for almost every computer.
Gopher will present the user with either a directory or a file. Most Gophers allow users
to search for information too.
mailto:
This is a special type of URL that lets you send e-mail messages.
news:
A link that points to a Usenet newsgroup must be declared using
this protocol. This is one of the most widely used internet services that organizes
peoples' comments according to the topic. These topics are called newsgroups and have
their own structure.
telnet:
A link that needs to open a telnet session must be declared with
this protocol. Telnet allows one computer to act as a terminal on another computer. Using
telnet, people can type on another computer as if they were directly connected. Most
browsers cannot open telnet sessions themselves but they will launch a separate telnet
client when such links are chosen.
wais:
WAIS stands for Wide Area Information Server. It
is a method for searching databases over the internet. It never became very popular
because both the server and client softwares are not very easy to use. Even though all WWW
browsers can access WAIS servers, most users prefer to use WAIS gateways.
http://
http:// is the most common protocol found on the
Web. This protocol defines how hypermedia files get from the World Wide Web server to your
computer intelligibly. A computer that stores and transmits WWW hypertext documents is
running software called an HTTP "server". To display those documents on your
computer, you have to have HTTP "client" software. This software is built into
every WWW browser that you use.
The second part of the URL defines the location of the server housing the file or information pointed to in the link. This can be done in one of two ways; either by using the domain name of the server, or by using its corresponding IP address. Since the Internet Protocol address is numeric and usually not easy to remember, most people use the domain name which usually describes the actual name of the site and is much easier to recall. This part of the URL starts after the double slashes (//) and ends at the single slash(/), if there is one. It can sometimes be very long, but it usually ends with a DOS-like extension following a period. The most common extensions for domain names are:
.edu educational sites, usually colleges and schools.
.com commercial sites, businesses etc.
.gov governmental sites, White House, Senate etc.
.org nonprofit organizations.
If the extension is something else, it is probably an abbreviation for a foreign country such as:
| Extention | .au | .br | .ca | .de | .fr | .ie | .jp | .nl |
| Country | Australia | Brazil | Canada | Germany | France | Ireland | Japan | Holland |
Country extension can follow other extensions also
These two components of the URL may or may not exist. It depends on the link that's being pointed to. Paths through directories are given by a forward slash (/) using the UNIX method for path definitions. Windows and DOS users beware that this is the opposite of the DOS backslash (\) used for defining paths.
A browser is the software used to navigate through the World Wide Web. It is client software that enables users to view the many kinds of information on the Web, such as HTML documents, FTP directories and gopher pages. Many different browsers are available now and every one can interact with server software. The most popular browser in use today is Netscape Navigator and Microsoft's Internet Explorer.
This Page was created by Carlo Armonici.©1997 Edited by Adriana Armonici .
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