What happens when you click on a weblink? Here's one answer: a request goes from your computer to a server identified by the URL of the desired link. The server then locates the webpage in its files and sends it back to your browser, which then displays it on your screen. Simple.

Well, the process was indeed like that once – a very long time ago. In the beginning, webpages were simple pages of text marked up with some tags that would enable a browser to display them correctly. But that meant that the browser, not the designer, controlled how a page would look to the user, and there's nothing that infuriates designers more than having someone (or something) determine the appearance of their work. So they embarked on a long, vigorous and ultimately successful campaign to exert the same kind of detailed control over the appearance of webpages as they did on their print counterparts – right down to the last pixel.

This had several consequences. Webpages began to look more attractive and, in some cases, became more user-friendly. They had pictures, video components, animations and colourful type in attractive fonts, and were easier on the eye than the staid, unimaginative pages of the early web. They began to resemble, in fact, pages in print magazines. And in order to make this possible, webpages ceased to be static text-objects fetched from a file store; instead, the server assembled each page on the fly, collecting its various graphic and other components from their various locations, and dispatching the whole caboodle in a stream to your browser, which then assembled them for your delectation.

All of which was nice and dandy. But there was a downside: webpages began to put on weight. Over the last decade, the size of web pages (measured in kilobytes) has more than septupled. From 2003 to 2011, the average web page grew from 93.7kB to over 679kB.

You can see this for yourself by switching on the "view status" bar in your browser; this will tell you how many discrete items go into making up a page. I've just looked at a few representative samples. The BBC News front page had 115 items; the online version of the Daily Mail had a whopping 344 and ITV.com had 116. Direct.gov had 71 while YouTube and Wikipedia, in contrast, came in much slimmer at 26 and 15 respectively.

Whether you view this as a good thing or not depends on where you sit in the digital ecosystem. Aesthetes (and graphic design agencies) drool over the elegance of pages whose look and feel is determined down to the last pixel. Engineers fume at the appalling waste of bandwidth involved in shipping 679kB of data to communicate perhaps 5kB of information. Photographers love the way their high-resolution images are now viewable on Flickr and Picasa. Futurists (and broadband suppliers) rejoice that this epidemic of obese webpages is driving a demand for faster (and more profitable) broadband contracts and point to the fact that communications bandwidth is increasing at a rate even faster than processing power.

Personally, I'm a minimalist: I value content more highly than aesthetics. The websites and pages that I like tend to be as underdesigned as they are cognitively loaded. Take for example, the home page of Peter Norvig, who is Google's director of research. In design terms it would make any graphic designer reach for the sickbag. And yet it's highly functional, loads in a flash and contains tons of wonderful stuff – such as his memorable demolition of the PowerPoint mentality in which he imagines how Abraham Lincoln's Gettysburg Address would look as a "presentation". Or his hilarious spoof of Einstein's "annual performance review" for 1905, the year in which he published the five papers that changes physics for ever. (Einstein, you may recall, was a humble patent clerk in Berne at the time.)

But in addition to these plums, Norvig's site is full of links to fantastically useful resources – such as the open source code that accompanies his textbooks. And it's as easy to navigate as anything produced by a web-design agency for £100,000 plus an annual service contract.

Sites like his remind one that the web is not just about shopping or LOLcats but is the most wonderful storehouse of information and knowledge that humanity has ever possessed.

Think of it as the Library of Alexandria on steroids. And remember that it's as accessible to someone in Africa on the end of a flaky internet connection as it is to a Virgin subscriber in Notting Hill who gets 50MB per second on a good day.