Now, a closer look at the inner workings of the Web

So now we know that the Internet is the publicly available worldwide system of interconnected computer networks that transmit data by packet switching using a standardised Internet Protocol (IP) and many other low-level protocols. Here, we'll elaborate, again, on inner workings - this time looking at one of the Internet's most prominent applications: The World Wide Web.

The Internet uses low-level protocols to exchange data. These few words are key to understanding the role of the Internet and they will help us to make a distinction between it and the Web.

Here, by low-level we mean something that has been broken down into essential parts. In contrast, high-level would mean something more sophisticated that consists of many composite parts and taken together, really mean something greater. Take our telephone system for example. Telephone lines exchange low level data in the form of electric impulses. The high level content of our telephone system, human conversation, is broken down to transmit electrical impulses to a receiver on the other end of the phone line before it is, in the blink of an eye, reassembled to create a meaningful communication link. Or take language itself as an example. The meaning of our conversations is high level information which in fact consists of many essential elements which can be broken down into increasingly more atomic or low level data, paragraphs, sentences, words, letters, in order to make exchange more efficient.

Now think of the Internet as the network plumbing that is required just to exchange low level data like a postal service routes letters.  And think of the web as one example of an application which uses this plumbing, but which is more concerned with managing high-level information, or content. Remember....the Web is created by a special application; it's an information space created by distributed software and coordinated by shared protocols. It too contains a method of exhange but instead of data packets (which the Internet exchanges), the Web exchanges instructions and documents with text and pointers to rich, meaningful content like sound, images, software programs, and video. And it is more. Think about that term information space. Unlike the Internet, which by itself is concerned only with communication for the purposes of exchange, the Web is also concerned with high-level purposes like managing and collaborating upon these documents; of creating a persistent environment for using information: discovering it, presenting it, interacting with it, exchanging it between devices, and so on.

Tim Berners-Lee (TBL) set out to create a universal document collaboration system.  He had the Internet and hypertext to work with, and SGML, a precursor of his HTML to work from.  He invented the Web by developing a few simple distributed applications (web browser, and web server), an addressing system, and a basic set of rules for requesting resources.

Take a moment to think about the open design that defines the Web.

What is a web browser?

What is a web server?

What is HTML? It's not as complex as you might think.

How is communication on the web governed?

How are web resources identified?

How does it all come together?