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Wonderful World Wide Web

You're sitting at home, biding you time reading the morning paper, when, like a bolt of lightning out of the blue, you're struck by one of those metaphysical question which gnaw at the souls of men. ``Who played Ta and Sa, the parents of the celebrated Chaka, on `Land of the Lost'?''. In the late 80's, when struck by such a issue so fundamental to existence, you'd have no choice but to summon all your will-power and banish such an interrogative to the nether reaches of your consciousness until you happened upon that very special of friend and were relieved of such a burden by one skilled in the arts of Library Science. However, today all one need do is fire up the nearest computer, go on-line, and point a browser to Google to sate this burning in the fore of you brain[*]. The world wide web is a wonderful thing. But of what is this wonderful thing made?

Hypertext Transfer Protocol, HTTP, is the core of the web. HTTP specifies the niceties that must be adhered to when your client-browser talks to a web server. HTTP lays bare the jurisprudence of courtly love between your client suitor and the server suited. For example, the HTTP standard says of first contact in this courtly dance...

A request message from a client to a server includes,
within the first line of that message,
the method to be applied to the resource,
the identifier of the resource, and
the protocol version in use.
Romantic stuff! (Andreas Capellanus' De amore has nothing on this!) HTTP relies, for its ways of wile, in great part upon two other standards Hyper-Text Mark-Up Lanuage, HTML, and Multipurpose Internet Mail Extensions, MIME.

MIME, the unsung paladin of the internet age, is a standard which specifies how various images, movies, pictures, and the like can be transmitted over a 7-bit ASCII connection. So, for example, in reply to a client's fervent entreaty, a server could encode an image of passion in letter of love using the courtly laws set forth in the MIME standards. MIME also lifts the client's burden in that it allows for the client to determine the type, image, movie, sound,..., of the data in this so received missive. MIME, strangely enough, was first formulated for the modern letters of love, email. Only later did MIME find its true calling, supplying the encoding for all manner of things beyond e-missives.

HTML, the Geraint of this wired world, is a standard which specifies how to annotate text with semantic information. What does that mean, you say. Let me explain using an example. Consider if you, in a courtly mode, were listing rules of love and wanted the world to know the path of true love. You decide that writing a book called De amore might be a good idea, but that's so $12^{th}$ century. Living in the $21^{th}$ century you decide the best course of action is to create a web page laying the path bare. You could emphatically and without doubt render your $4^{th}$ rule, say, in this HTML-prose by marking your text with emphasis where required

4. When a lover suddenly has sight of his beloved, his heart beats <em>wildly</em>.
by using the <em>...</em> HTML tags. These tags indicate that any text which is contained within their bounds should be interpreted with an added emphasis. Just as an exclamation point `!' adds emphasis to a sentence (Shut da' hell up!), so <em>...</em> adds emphasis to the text enclosed. There are literally hundreds of other HTML tags each of which encodes some semantic nugget. One other not so secret power of HTML is the fact that HTML documents can refer to one another through the use of a Uniform Resource Identifiers, URI. A URI is simply a little string of text which unambiguously identifies how to find a resource. This ``trinity plus one'' (HTTP, MIME, HTML, and URI) is the core of the web, a web into which we will now more deeply peer.


next up previous contents
Next: URI's Relative and Absolute Up: Basic Web Concepts Previous: Basic Web Concepts   Contents
Andre Merzky 2004-05-13