Once a small and simple collection of computers run by the Defence Department, is now a massive world wide network of computers, what we call the 'Internet'. The word "Internet" literally means "network of networks." In itself, the Internet is composed of thousands of smaller local networks scattered throughout the globe. It connects roughly 15 million users in more than 50 countries a day. The World Wide Web (WWW) is mostly used on the Internet. The Web refers to a body of information, while the Internet refers to the physical side of the global network containing a large amount of cables and computers.
The Internet is a 'packet-switching' computer network. When a person sends a message over the Internet, it is broken into tiny pieces, called 'packets'. These packets travel over many different routes between the computer that it is being sent from to the computer to which it is being sent to. Phone lines, either fibre-optics or copper wires ones, carry most of the data packets. Internet computers along the path switch each packet that will take it to its destination, but no two packets need to follow the same path. The Internet is designed so that packets always take the best available route at the time they are travelling. 'Routers' which are boxes of circuit boards and microchips, which do the essential task of directing and redirecting packets along the network. Much smaller boxes of circuit boards and microchips called 'modems' do the task of interpreting between the phone lines and the computer. The packets are all switched into a destination and reassembled by the destination computer. Today's Internet contains enough repetitious and interconnected circuits simply to reroute the data if any portion of the network goes down or gets overloaded.
The packet-switching nature of the Internet gives it sufficient speed and flexibility to support real-time communication, such as sending messages to other people in a chat environment (IRC). Every packet is written in a particular protocol language, called TCP/IP, which stands for Transmission Control Protocol/Internetworking Protocol. This protocol is the common language of the Internet, and it supports two major programs called File Transfer Protocol (FTP) and Telenet. FTP lets the transfer files from one Internet computer to another. Telnet lets a person to log into a remote computer. They have combined these two tools in complex ways to create the Internet tools such as Gopher, the World Wide Web and IRC.
Some collections of phone lines and routers are larger and more powerful than others. Spirit and MCI both have each built collections of phone lines and routers that crisscross the United States and can carry large amounts of data. There are six companies in the US with large, nationwide networks of high-speed phone lines and routers. These companies include, MCI, Sprint, AGIS, UUNet/AlterNet, ANS, and PSI. They make up what they often call the 'Internet Backbone'.
Data packets travelling on a 'backbone' network stay within that network for much of their journey. The reason is that there is only a handful of places where the backbone networks meet. For example, 1a packet travelling on a Sprint circuit to a Sprint router, can only transfer to an MCI circuit at certain places. This is just like how certain city streets often run parrel to each other for many miles before reaching an intersection. These intersections that they call 'Network Access Points' (NAP) are very crucial to the transmission of data on the Internet.
A Web is a program running on a computer who's only purpose is to serve documents to other computers when asked. A Web client is a program that interfaces (talks) with the user and requests documents from a server as the user requests them. The server only operates when a request for a document is made. The process of how this work is very simple, one example is; Running a Web browser, the user selects a piece of hypertext connected to another text -"Planes."
The Web client connects to a computer specified by a network address somewhere on the Internet and asks that computer's Web server for "Planes." The server responses by sending the text and any other media within the text (this includes pictures, sounds, movies) to the users screen. The World Wide Web does thousands of these transactions per hour throughout the wold, creating a web of information.
They call the language that the Web client and servers use to talk with each other the 'Hypertext Transmission Protocol' (HTTP). All Web clients and servers must be able to speak HTTP to send and receive hypermedia documents.
The standard language the Web uses for creating and recognizing hypermedia documents is the 'Hypertext Markup Language' (HTML). Another formatting language used for Web documents is 'Standard Generalized Markup Language' (SGML). HTML is widely liked because of its ease of use. Web documents are usually written in HTML and are usually named with the suffix '. html'. HTML documents are nothing more than standard 7-bit ASCII files with formatting codes that contain information about the layout (text styles, document titles, paragraphs, lists and hyperlinks). Hyperlinks are links in the document to go to other documents or another Web sight. HTML uses what they call 'Uniform Resource Locators' (URL) to represent hypermedia links and links to network services within documents. The first part of the URL (before the two slashes) specifies the method of access. The second is typically the address of the computer where the data or service is found. Further parts may specify the name of files, the port to connect to, or the text to search for in a database.
Most Web browsers allow the user to specify a URL and connect to that document or service. When selecting hypertext in an HTML document, the user is actually sending a request to open a URL. In this way, they can make hyperlinks not only to other texts and media, but also to other network services.
The powerful, sophisticated access that the Internet provides is truly amazing. It is spreading faster than cellular phones, and fax machines. The amount of people connecting to the Internet is growing at a rapid rate, along with the number of "host" machines with direct connection to TCP\IP. The main reason that the Internet is flourishing so rapidly is because of the freedom, there is no one who actually owns the Internet and no rules for users. As the Internet grows, many new activities are joining in, like 'Internet Radio', which will support real-time call-in shows and music to be sent over the Internet. As the Internet is expanding into another decade, it will become even more interesting and complex.
1.John Quarterman, The Matrix: Computer Networks and Conferencing Systems Worldwide (Bedford, MA: Digital Press, 1990), 42.
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