1.1 The World Wide Web (WWW)

 

The world wide web is a collection of computers that offer access to services (web, ftp, mail, telnet). Communication across the world wide web depends on the TCP/IP stack of protocols.

 

What Exactly is the Internet?

The Internet is best characterized as "the biggest network of computer networks on earth."

A computer network is a data communications system for hardware and software. In part, a network includes physical infrastructure like wires, cables, fiber optic lines, undersea cables, and satellites. The other part of a network is the software to keep it running. The Internet is a network, but it is not just a single network.

From the Free Online Dictionary of Computing, we get this definition from its entry for Internet:

"The Internet is the largest internet (with a small "i") in the world."

We then get this definition from its entry for internet:

"Any set of networks interconnected with routers. The Internet is the biggest example of an internet. "

We then get this definition from its entry for router:

"A device which forwards packets between networks. The forwarding decision is based on network layer information and routing tables, often constructed by routing protocols."

While this might seem like too terse or technical of an answer, it is technically correct. An internet (small i) is simply a set networks connected by devices that exchange data with each other in packets. The Internet is the name given to the largest set of interconnected internets in the world. In particular, the method by which this data is exchanged on the Internet is through the TCP/IP protocol suite.

You can keep the difference between "Internet" and "internet" straight by remembering this: When you mention "internet," you must always identify which internet you mean--there are millions and millions of internets in the world. However, when you say "Internet," there can be no doubt about what you speak: There is precisely one and only one Internet in the world.

The Internet is not run by any one organization nor operated by any single agency. This makes a definition of the Internet that identifies a single organization who owns it or runs it impossible. In truth, the Internet is run by a vast patchwork of telecommunications organizations, research centers, universities, and private individuals through their mutual cooperation to ensure the exchange of data amoung their networks in packets using a common TCP/IP protocol.

Read over this presentation about the Internet to get more ideas about what the Internet is and how it works.

What is the World Wide Web?

From the Free Online Dictionary of Computing, we get this definition from its entry for WWW:

"An Internet client-server hypertext distributed information retrieval system."

The Web is not a network. The Web is not the Internet itself. The Web is not a proprietary system like AOL. Instead the Web is a system of clients (Web browsers) and servers that uses the Internet for its data exchange.

Exercise: Define the Internet and Web

If someone stopped you in the street and demanded to know your definition of the Internet and World Wide Web, what would you say? Define the Internet in your own words. How is the Internet and Web different from AOL?

 

1.2 Hypertext and Hypertext Markup Language

 

The Hypertext Transfer Protocol (HTTP) is the set of rules for exchanging files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. Relative to the TCP/IP suite of protocols (which are the basis for information exchange on the Internet), HTTP is an application protocol.

Essential concepts that are part of HTTP include (as its name implies) the idea that files can contain references to other files whose selection will elicit additional transfer requests. Any Web server machine contains, in addition to the HTML and other files it can serve, an HTTP daemon, a program that is designed to wait for HTTP requests and handle them when they arrive. Your Web browser is an HTTP client, sending requests to server machines. When the browser user enters file requests by either "opening" a Web file (typing in a Uniform Resource Locator) or clicking on a hypertext link, the browser builds an HTTP request and sends it to the Internet Protocol address indicated by the URL. The HTTP daemon in the destination server machine receives the request and, after any necessary processing, the requested file is returned.

The latest version of HTTP is HTTP 1.1

 

 

1.3 Microsoft Front Page

 

Microsoft Front Page is a tool that was introduced to help web designer and developers in the creation and maintenance of websites. The main task of Front Page is to simplify the writing of HTML by allowing the user to write and edit HTML documents without the need to know or manage HTML tags.

MS Front Page will convert user input including graphics, text, and tables to HTML documents. MS Front Page will also handle web-site management (upload of files, or download of files). Microsoft also added the ability to manipulate code and databases through the same interface.