The Internet and the World Wide Web: Some Key Concepts

The Internet and the World Wide Web:
Some Key Concepts

by Agatha Taormina

Origin of the Internet	The Internet is a global system of computer networks that exchange information through the use of common communications standards, called protocols. These standards are platform-independent, i.e., they allow any computer, regardless of make, model, or operating system, to communicate with any similarly equipped computer. The Internet had its beginnings at the U.S. Department of Defense’s Advanced Research Projects Agency (ARPA). This agency's mission was to develop a communication system organized in a network capable of re-establishing links between computers in the event of an attack. In 1969 the first ARPANET (Advanced Research Projects Agency Network) was installed at UCLA. Other ARPANETS at the University of California at Santa Barbara, Stanford Research Institute, and the University of Utah soon followed. Email programs were developed in the 1970s and early 1980s; at this time personal computers began to be widely available.
Tools and Features of the Internet	The Internet has several components: Telnet—a way to connect to a host computer and use its facilities Gopher—a text-based program designed to locate and download files available on the Internet FTP—file transfer protocol, a method for transferring files via the Internet Email—an electronic messaging service Usenet—a network of newsgroups World Wide Web—the Internet’s graphical and hypermedia interface
Birth of the World Wide Web	The World Wide Web, also referred to as WWW or the Web, originated at CERN (acronym for Conseil Europeen pour la Recherche Neclaire), the European Laboratory for High Energy Physics in Bern, Switzerland. Tim Berners-Lee, currently head of the W3 Consortium, the organization responsible for setting standards for displaying information on the Web, first conceived of a way to make Web material available to desktop computers. 1991—first text browser developed 1993—NCSA Mosaic developed by Marc Andreesen at the National Center for Supercomputing Applications at the University of Illinois; this was the first graphical Web browser, i.e., the first browser capable of displaying pictures. 1994—Andreesen and James D. Clark, the founder of Silicon Graphics, founded Mosaic Communications October 1994—Netscape Navigator, a graphical browser, became available November 1994—Mosaic changed its name to Netscape Communications August 1996—Microsoft Internet Explorer 3.0 was released; this was the first Microsoft-developed browser software which challenged Netscape's domination of the browser software market Currently both browsers are not only free, but also available in browser suites bundled with email messaging software, Usenet and discussion group software, and simple WYSIWYG html editors.	WYSIWYG=What You See Is What You Get; Pronounced whizzy-wig
Web Sites and Web Pages	A web page is an individual file. A web site is a collection of related pages (i.e., files). The home page is the first or cover page of a web site. Important: name this home page default.htm.	When browsers arrive at a web address, they automatically look for a default file to open first.
HTML	The actual content of web pages is written in HTML. HTML is a simple, platform-independent, mark-up language written in ASCII plain text. It consists of paired tags that work like on/off switches to affect the way material placed between the tags is displayed on a computer monitor. Tags (directions) are always enclosed in angle brackets and usually paired, e.g., <TAG></TAG>; note the forward slash in the closing tag. Many tags can contain attributes that further modify the look of your page, e.g.,<TAG ATTRIBUTE=VALUE></TAG> Material between the paired set of tags is what appears on the monitor, e.g., <TAG>Viewable Text</TAG>	HTML=HyperText Markup Language
Example	<B>Hello!</B> becomes Hello!
Web Site Addresses	A web site address is called a URL. It consists of several parts: the protocol the domain name the directory path the filename	URL = Uniform Resource Locator
	The protocol tells the computer that a web page is being transferred. This transfer protocol is called http.	http= HyperText Transfer Protocol
	The next part of the URL tells the browser where the actual file is located. The file resides on a server with a designated domain name. The domain name is the first part of the web site address.
	Next comes the directory path that tells the browser which folder on the server contains the file.This is the pathname. The pathname could actually be a series of folders within folders.	e.g. my home page is in a folder called ataormina inside a folder called home on a server with the domain name of nvcc
	The particular file is identified by a pathname that follows the domain name in the URL. Note: If the home page of your web site, which is contained in your folder, is named default, the browser opens that file automatically without the visitor's need to type it in the Location box.
	Thus, my home page, which has a file name of default.htm, can actually be found at http://www.nvcc/home/ataormina
Browsers	A browser is a software program used by the computer to interpret HTML and display it on your monitor. The way your pages look to the visitor depends in part on the type and version of browser and the size of the monitor being used. Some popular graphical browsers Microsoft Internet Explorer Firefox Safari SeaMonkey
	Unfortunately, these browsers, which effectively dominate the home computer market, interpret HTML in slightly different ways. Sometimes the same browser interprets HTML in different ways in different versions. Despite the efforts of the W3 Consortium there is no uniform standard for HTML. Thus a web page designer must be aware of the different ways these two leading browsers might display the web page files.