The World Wide Web

Since I was first exposed to the Internet back in 1995, people have erroneously had a tendency to use the terms Internet and World Wide Web interchangeably. It may take the mind of a true geek to really care about the difference, but the World Wide Web is actually only a small fraction of the Internet.

This article is the first in a series meant to supplement the web design course that I’m currently teaching at SUN Area Career & Technology Center. I will define the Internet and the World Wide Web, talk briefly about their history, and discuss a few of the web’s defining features.

Introduction

When someone tells us to "get on the Internet and look something up" we generally understand that what they mean to say is open a web browser, go to a search engine, and search for a specific term. If we wanted to be true geeks (and annoy our friends), we could simply sit back in our chairs and do nothing when someone asks us to do this, because there’s a pretty good chance that our computers are already on the Internet. The distinction may sound trivial, but the difference between the Internet and the World Wide Web isn’t quite as subtle as most people think.

The Internet

The Internet is just a large network of computers. It also happens to be the largest network in the world, composed of many thousands of smaller networks and computers which communicate with one another using a standard communications protocol called IP, or Internet Protocol. IP allows devices on the Internet to find and send each other data, but IP sees the data it transmits simply as groups of zeros and ones. It doesn’t know and doesn’t care if you are using the Internet to send an email, watch a movie, or check the weather.

Think of IP as the vocal chords and ears of the web. The vocal chords make sounds and the ears hear them, but these organs don’t understand the ideas that they’re used to convey. The information they send and receive is passed on to the brain to be processed. Likewise IP is responsible for sending and receiving data, but the data has no context and so another service is required to make sense of it.

Many services exist on the Internet, and it’s likely that you’ve already used more than one. E-mail is one such service, as are instant messaging and of course the World Wide Web. Most services have a common name we use to refer to them in conversation and another name for the service-specific protocols which they use to communicate over the Internet. E-mail, for example, is a service which needs little explanation and it uses the POP3, SMTP, and IMAP protocols of communication. Most casual users don’t know that, nor should they have to.

The World Wide Web

The World Wide Web, or just the Web for short, is one of many services that exist on the Internet. The web is at it’s most basic level a collection of interconnected documents distributed across the Internet. Documents on the web reside on special computers called web servers that understand the web’s primary communication protocol which is called HTTP (HyperText Transfer Protocol). Users like you and me can download and view these documents using a program called a web browser that understands how to request them from a web server using the HTTP protocol.

So What’s the Difference?

The difference between the Internet and the World Wide Web is that the Web is only a small part of the Internet. Though it is currently the most popular service the Internet has to offer, it is still just one of many. Saying that the Web is the same as the Internet is like saying that Comedy Central is the same as television.

Defining Characteristics of the World Wide Web

The Web is a distributed, decentralized service. No single company, government, or individual owns the Web and therefore it can’t just be shut down by removing a computer from the Internet. A single website can be taken off the Web, but the web itself will survive as long as it remains a useful service.

The Web is a collection of interconnected documents that can be downloaded from web servers by a program called a web browser using a protocol called HTTP. There were a lot of big words in that sentence, so let’s explore and define some of the important terms in detail.

A Collection of Interconnected Documents

Every document on the Web has an address called a URL (Universal Resource Locator). A URL specifies the name of the web server on which a document resides and the path to a file. A URL that doesn’t specify a path or filename points to the website’s home page. We say that documents on the Web are interconnected because one document can refer to the URL of another document, allowing users to navigate between related documents.

Documents on the Internet are created in a file format called HTML (HyperText Markup Language). A markup language is a file format containing text and annotations that provide the text with structure, meaning, and formatting. HTML is one of many such languages. What makes HTML unique is that it uses annotations called tags to turn regular text into hypertext, an interactive text format which can link words to related documents. HTML uses an annotation (or tag) called a hyperlink to link text to another document on the web by referring to it’s URL. When the hyperlinked text is clicked, the linked document will be downloaded.

Web Servers

Most services on the Internet are based on a concept called client-server architecture. What this means is that there are two computers or individuals involved in all communication: one which provides a service (the server) and another which accesses that services (the client). A web server is a computer on the Internet which provides the World Wide Web service, technically referred to as the HTTP protocol. A web server listens for HTTP requests and responds by locating the requested document on it’s hard drive and sending it as the contents of it’s HTTP response.

Web Browsers

A web browser is an HTTP client program. That is, web browsers understand how to make requests to web servers using the HTTP protocol. When a web server sends a browser the HTML page that it requested, the browser is also responsible for understanding how to interpret the HTML language and display the document.

Conclusion

After reading this article you should understand that the World Wide Web (or Web, or WWW) is just one of many services available on the Internet. The Web is a decentralized service provided by many computers connected to the Internet called web servers. Web servers provide HTML documents that utilize a type of text annotation called a hyperlink to link to one another and provide the user with the ability to navigate to related documents to find more information on a given topic. Users of the Web use a program called a web browser. A web browser uses the address, or URL, of a document on the Web to request it from a web server using the HTTP protocol.

I had a professor in college that often said regarding computer science that you learn what’s going on in the first class, and you learn what’s really, really going on in the last class. I’ve left out many specifics while writing this article, but it provided you with a foundation for understanding the World Wide Web from which you can expand and learn not only how to use the Web, but also create your own web content.