3.4 The internet is not the world wide web

Part of the internet

At its simplest, the world wide web is nothing more than the part of the internet that can be accessed through the HyperText Transfer Protocol (HTTP) – another one of those standards that helps glue the internet together. HTTP allows two computers to exchange information as a series of requests (e.g. a request from your computer for a copy of the To do list page for this course) and responses (e.g. an Open University server delivers the contents of that page).

HTTP relies on TCP to set up the connection between the two machines, and it in turn uses IP to send and receive data. The most common applications that understand HTTP messages are web browsers such as the one you are using right now.

The world wide web is an example of hypertext – documents joined together using links. Every time you click on a link, HTTP is used to request a new page from a web server using TCP port 80. The content for the page is delivered to your computer, again through port 80 and interpreted by a web browser which formats the data in a human readable manner.

Designed to be open

The world wide web was designed from the very start to be an open environment which encouraged people to set up their own web servers and to write web pages. To encourage its uptake, all of the documentation that explains HTTP, and other standards that have grown up around the web, are publicly available to anyone wishing to develop software for the web. Likewise, the computer language used to format web documents, the HyperText Mark-up Language (HTML) is not only fully documented online, but is extremely easy to use.

Apart from the world wide web, the internet itself is used for a much wider range of services including email, instant messaging and file transfers. The internet’s flexibility comes down to the flexibility of the underlying protocols – so long as information can be stored in IP datagrams – and just about anything can – it can be moved around the internet.

Interview with Tim Berners-Lee

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Transcript

NARRATOR

In 1980, a young software consultant called Tim Berners-Lee wrote a programme called ENQUIRE. It involved the use of hypertext, links that allow users to jump directly from one computer page to another. It's sowed the intellectual seeds of an information revolution – the world wide web.

In the late 1990s, Tim gave several interviews against rather noisy backgrounds for the Open University series TheWebStory.com.

TIM BERNERS-LEE

The web is an abstract space of information. The web is a space of pages, of documents, of pictures, which are linked together. And the links are abstract links. Now in fact, for the web to exist, all this information about the links and about the documents is transferred over the internet.

NARRATOR

Tim's pioneering idea for the world wide web emerged in 1989, when he was working for CERN, the European organisation for nuclear research.

TIM BERNERS-LEE

I was just frustrated with a lack of interoperability, the fact that people were championing different documentation systems and help systems. And I tried experimenting with actually taking all the documents in one system and making it appear as though they were in this help system. So I looked at the mapping between the two, and eventually I realised that this little hypertext programme I'd been playing with 10 years before was, in a sense, the key, and that if you made a global hypertext system, any of these systems could be represented in terms of it.

And so suddenly, this was the answer to making any system available without disturbing it, even. That was the key thing. Without putting constraint on somebody, forcing them to use a particular machine, forcing them to store their documents in a particular format.

It just said, all right, let's not force any of those issues. Let's just second-guess them. Let's step above them, and let's say, whatever format you put your document in, let's say that it's part of the one universal space. And let's find a way of making an identifier for it. And once you had that idea, it's really pretty unstoppable.

So when I said, hey, I think we should make a completely general global hypertext system, the very proper answer at CERN was, well, that's fine, but it's not what we're here for. So in fact, it was only because my boss, Mike Sandel, who had a sort of twinkle in his eye, and thought, hm, I don't know what exactly this is about, but I have a feeling that it sounds kind of exciting.

And he said, well, why don't you spend the next couple of months – you know, I won't complain if you just go and write the programme. If Mike hadn't said that, if I'd had to go through the process of trying to get a formal project approved, it would never have happened.

NARRATOR

Tim's brilliant idea was to make documents located on one computer appear to be located in a window on another computer. It took Tim and his colleague Robert Cailliau two years to develop and refine the protocols that could make this happen.

TIM BERNERS-LEE

When you're looking at a web page and you click on a hypertext link, then hidden behind the actual text of what's written there is the identifier of some other page. When you click on it, then the programme which shows you that page looks up the identifier. An identifier's one of these things which starts with http://.

Now the http means if you want to get at this thing, this is how you do it. You take the rest of the string, the rest of the characters, and the first bit is something like www.acme.com. And that is the is name of a computer, in fact.

So the first thing you do is you go out to another computer you know which knows about the native computer and says, hey, where do I find this? And you get back a computer number, like 28.34.6.12. Something looking more like a telephone number of the other computer. Then your computer uses that to start communicating with the other computer, which has got the information.

And what it does, it sends a very simple message. It just says get, and then it gives the rest of all the other characters left. So when you look at something which says http:// – that means use hypertext transfer protocol. www.something.com – that means go to this computer. Slash, gobbledy-gook-gobbledy-gook.

Gobbledy-gook-gobbledy-gook, you don't have to understand. All you do is you know that's what you asked for. So it makes a connection and it sends a very simple command, which is get gobbledy-gook-gobbledy-gook. And the response is that the information about how to put up that page comes back across the internet, across that connection.

So it's really very simple. It's just, get me gobbledy-gook. Here's gobbledy-gook.

NARRATOR:

To start with, the web was limited to developments within the CERN community. Then in August 1991, Tim and his colleagues launched the first publicly available website, a milestone in the history of the internet.

TIM BERNERS-LEE

A lot of people ask, what was it like when the web – when it suddenly exploded? When – but it didn't. It didn't suddenly explode. What happened was that it was, for the first two years, a big, hard slog trying to persuade everybody that the idea of global hypertext was not too crazy, or too complicated, or too confusing, or too expensive, or whatever. And in fact, that it was very simple, and in fact, it would save time, et cetera.

So with my fellow evangelist and colleague, Robert Cailliau, we went around to conferences and we went and talked to people individually within the high-energy physics community – which was basically paying our salaries, remember. So I had to persuade them this was important for highenergy physics. And we, at the same time, sent our some emails and some articles to newsgroups and things.

And it was not apparent that it was going to actually make it for a long time. But the interesting thing was that when I looked at the logs of the servers – the first server was called info.cern.ch. And the load on that server, which started off serving 10, 100 hits a day in the summer of '90 – the load on that server went up exponentially during the next 12 months.

And then when I looked back the year after that and made a graph of the second 12 months, it was again exactly the same-shaped exponential curve. So after a while, I started plotting it on a log scale so that you could see it as it went up from the hundreds to the thousands to the tens of thousands. And the load on that server was just – as the time went on from the summer of '91, summer of '92, summer of '93, summer of '94 – the load on the server just went on increasing by a factor of 10 every year.

NARRATOR

But the growing success of the world wide web only partially realised Tim's initial dream of what might be possible.

TIM BERNERS-LEE

The first part of it was, wouldn't it be great if we had this universal information space, and everybody could be in equilibrium with it so they could exchange information very fluidly through it? Wouldn't this do something amazing for humankind, if we were connected through this information space? That was the dream, part one.

And the other half of the dream was, suppose you have a situation where any idea which is worth typing in, worth clicking in with a mouse, is in the web? Then maybe we should bring back the computers, the computers which have gotten out the way. The computers which have hidden, made themselves scarce, and just produced this information for us. Maybe we'll be able to use them again. Maybe we'll be able to write programmes which can analyse what on Earth our society is like, what on Earth we are trained to do.

That was the second part of the dream. And that's not there at all. So that, we need a whole lot more technology in the web. We need machine-understandable information. We need digital signature. We need a web of trust. We need logical reasoning out there on the web. That is going to be yet another revolution.

I think it's going to be as dramatic as the web phase I, if you like. And we haven't started yet. So really, if you think everything's over, you're completely wrong. This is just the start. We're just figuring out how to make these global revolutions using technology, and how to make them be a good thing for humankind. So jump on board now, because it's just speeding up.

ANNOUNCER

From the Open University. For more information, go to www.open.ac.uk/use.

End transcript

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Listen to this interview. Towards the end, Tim Berners-Lee mentions a number of things that will be needed to make the world wide web achieve its full potential. One of these is digital signatures, which can be achieved using cryptography – our topic for next week.

Next, you have an opportunity to review your learning of the course so far in the Week 4 compulsory badge quiz.