of content, and therefore know exactly how it is built. We don’t do
that with human brains, or not yet.
Content is in
fact organized in repetitive layers, each describing the previous one, and each
time in two parts, that of the description, and that of the data themselves. In
the computer world, the description of data is called metadata. For
example, let’s consider a music piece registered on a hard disk. What we have
here is the first level of content data, that representing the notes of music.
What the description associated with those data does is make the format
explicit, so that we know how to decode the signal on the disk. For example,
the description can say that the music is represented using the familiar MP3
format. Thus we have a first piece of content, the combination of the music and
the description of the format used to represent it. Therefore, we will go one
step further, by describing that new content, giving it a name, say Like a
Virgin, the song by Madonna. Here we go: we have a yet another, more elaborate piece
of content, one that is identified by name. Let’s go another step up, by
combining that song of Madonna with another song, say Material Girl; we can
describe the assembly of the two songs, and give that a description, that of
the second album of Madonna. What was its title? In fact, it was Like a Virgin;
the album had the same name as the song of its first track. But the computer is
not confused, because in one case Like a Virgin is associated with a single
song, in the other it’s associated with an assembly of songs, in this case an
album. So here we’ve seen how content is built up, in an elegant architecture
taking simpler elements, structuring each layer into description and content,
and then going up from there.
It is only
recently that a model of the world of computer networks has been developed that
encompasses all aspects of network development in a single framework. That has
come by the meeting of two disciplines of computer science, in the end of the
1990’s and the beginning of the 2000’s. The first discipline is the Web and its
progressive structuring, with the alluring presence of its founder, Tim
Berners-Lee. Berners-Lee invented the Web and to this day has been a major
influence on its development. The second discipline is Artificial Intelligence,
and particularly the part of it which is concerned by the representation of knowledge
in computers. You guessed it; the convergence is that of making the network
knowledgeable.
Central to the
discipline of Web development is Berners-Lee’s invention of the Resource
Description Framework. The idea goes as follows. If I have an album of
Madonna on the hard disk of a computer somewhere, how does another computer on
the network know about it? Is there any way to devise a universal scheme that
allows identifying any resource in the world, anywhere on the network? Because
Berners-Lee is such a prescient thinker, he made the question even larger. If a
computer wants to designate something that is not in a computer, why shouldn’t
that be possible also? So here it is: Berners-Lee wanted to have a way to name
anything in the world, whether on a computer or not, so that computers could
have access to all the knowledge in the world. Of course, since we humans are
the ultimate users of the computers, thanks to Berners-Lee’s invention, we too
can describe any piece of content in the world, be it a song by Madonna, the
description of a tree in the Amazon or a black hole far away in the universe.
So, Berners-Lee called his invention a Uniform Resource Identifier (URI). The genius in the
invention is that he had disconnected the naming of things from the description
of the things themselves. What he really did is bring to the computer world
something that is very natural to humans. We can talk about a bird without
speaking about a particular bird, that bird. When we talk about a bird
in general, with no specific bird in mind, we are using what’s known in
linguistics as the connotation
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