1 The importance of "permissionless innovation"

The thing that is most extraordinary about the internet is the way it enables permissionless innovation. This stems from two epoch-making design decisions made by its creators in the early 1970s: that there would be no central ownership or control; and that the network would not be optimised for any particular application: all it would do is take in data-packets from an application at one end, and do its best to deliver those packets to their destination.

It was entirely agnostic about the contents of those packets. If you had an idea for an application that could be realised using data-packets (and were smart enough to write the necessary software) then the network would do it for you with no questions asked. This had the effect of dramatically lowering the bar for innovation, and it resulted in an explosion of creativity.

What the designers of the internet created, in effect, was a global machine for springing surprises. The web was the first really big surprise and it came from an individual – Tim Berners-Lee – who, with a small group of helpers, wrote the necessary software and designed the protocols needed to implement the idea. And then he launched it on the world by putting it on the Cern internet server in 1991, without having to ask anybody's permission.

2 The web is not the internet

Although many people (including some who should know better) often confuse the two. Neither is Google the internet, nor Facebook the internet. Think of the net as analogous to the tracks and signalling of a railway system, and applications – such as the web, Skype, file-sharing and streaming media – as kinds of traffic which run on that infrastructure. The web is important, but it's only one of the things that runs on the net.

3 The importance of having a network that is free and open

The internet was created by government and runs on open source software. Nobody "owns" it. Yet on this "free" foundation, colossal enterprises and fortunes have been built – a fact that the neoliberal fanatics who run internet companies often seem to forget. Berners-Lee could have been as rich as Croesus if he had viewed the web as a commercial opportunity. But he didn't – he persuaded Cern that it should be given to the world as a free resource. So the web in its turn became, like the internet, a platform for permissionless innovation. That's why a Harvard undergraduate was able to launch Facebook on the back of the web.

4 Many of the things that are built on the web are neither free nor open

Mark Zuckerberg was able to build Facebook because the web was free and open. But he hasn't returned the compliment: his creation is not a platform from which young innovators can freely spring the next set of surprises. The same holds for most of the others who have built fortunes from exploiting the facilities offered by the web. The only real exception is Wikipedia.

5 Tim Berners-Lee is Gutenberg's true heir

In 1455, with his revolution in printing, Johannes Gutenberg single-handedly launched a transformation in mankind's communications environment – a transformation that has shaped human society ever since. Berners-Lee is the first individual since then to have done anything comparable.

6 The web is not a static thing

The web we use today is quite different from the one that appeared 25 years ago. In fact it has been evolving at a furious pace. You can think of this evolution in geological "eras". Web 1.0 was the read-only, static web that existed until the late 1990s. Web 2.0 is the web of blogging, Web services, mapping, mashups and so on – the web that American commentator David Weinberger describes as "small pieces, loosely joined". The outlines of web 3.0 are only just beginning to appear as web applications that can "understand" the content of web pages (the so-called "semantic web"), the web of data (applications that can read, analyse and mine the torrent of data that's now routinely published on websites), and so on. And after that there will be web 4.0 and so on ad infinitum.

7 Power laws rule OK

In many areas of life, the law of averages applies – most things are statistically distributed in a pattern that looks like a bell. This pattern is called the "normal distribution". Take human height. Most people are of average height and there are relatively small number of very tall and very short people. But very few – if any – online phenomena follow a normal distribution. Instead they follow what statisticians call a power law distribution, which is why a very small number of the billions of websites in the world attract the overwhelming bulk of the traffic while the long tail of other websites has very little.

8 The web is now dominated by corporations

Despite the fact that anybody can launch a website, the vast majority of the top 100 websites are run by corporations. The only real exception is Wikipedia.

9 Web dominance gives companies awesome (and unregulated) powers

Take Google, the dominant search engine. If a Google search doesn't find your site, then in effect you don't exist. And this will get worse as more of the world's business moves online. Every so often, Google tweaks its search algorithms in order to thwart those who are trying to "game" them in what's called search engine optimisation. Every time Google rolls out the new tweaks, however, entrepreneurs and organisations find that their online business or service suffers or disappears altogether. And there's no real comeback for them.

10 The web has become a memory prosthesis for the world

Have you noticed how you no longer try to remember some things because you know that if you need to retrieve them you can do so just by Googling?

11 The web shows the power of networking

The web is based on the idea of "hypertext" – documents in which some terms are dynamically linked to other documents. But Berners-Lee didn't invent hypertext – Ted Nelson did in 1963 and there were lots of hypertext systems in existence long before Berners-Lee started thinking about the web. But the existing systems all worked by interlinking documents on the same computer. The twist that Berners-Lee added was to use the internet to link documents that could be stored anywhere. And that was what made the difference.

12 The web has unleashed a wave of human creativity

Before the web, "ordinary" people could publish their ideas and creations only if they could persuade media gatekeepers (editors, publishers, broadcasters) to give them prominence. But the web has given people a global publishing platform for their writing (Blogger, Wordpress, Typepad, Tumblr), photographs (Flickr, Picasa, Facebook), audio and video (YouTube, Vimeo); and people have leapt at the opportunity.

13 The web should have been a read-write medium from the beginning

Berners-Lee's original desire was for a web that would enable people not only to publish, but also to modify, web pages, but in the end practical considerations led to the compromise of a read-only web. Anybody could publish, but only the authors or owners of web pages could modify them. This led to the evolution of the web in a particular direction and it was probably the factor that guaranteed that corporations would in the end become dominant.

14 The web would be much more useful if web pages were machine-understandable

Web pages are, by definition, machine-readable. But machines can't understand what they "read" because they can't do semantics. So they can't easily determine whether the word "Casablanca" refers to a city or to a movie. Berners-Lee's proposal for the "semantic web" – ie a way of restructuring web pages to make it easier for computers to distinguish between, say, Casablanca the city and Casablanca the movie – is one approach, but it would require a lot of work upfront and is unlikely to happen on a large scale. What may be more useful are increasingly powerful machine-learning techniques that will make computers better at understanding context.

15 The importance of killer apps

A killer application is one that makes the adoption of a technology a no-brainer. The spreadsheet was the killer app for the first Apple computer. Email was the first killer app for the Arpanet – the internet's precursor. The web was the internet's first killer app. Before the web – and especially before the first graphical browser, Mosaic, appeared in 1993 – almost nobody knew or cared about the internet (which had been running since 1983). But after the web appeared, suddenly people "got" it, and the rest is history.

16 WWW is linguistically unique

Well, perhaps not, but Douglas Adams claimed that it was the only set of initials that took longer to say than the thing it was supposed to represent.

17 The web is a startling illustration of the power of software

Software is pure "thought stuff". You have an idea; you write some instructions in a special language (a computer program); and then you feed it to a machine that obeys your instructions to the letter. It's a kind of secular magic. Berners-Lee had an idea; he wrote the code; he put it on the net, and the network did the rest. And in the process he changed the world.

18 The web needs a micro-payment system

In addition to being just a read-only system, the other initial drawback of the web was that it did not have a mechanism for rewarding people who published on it. That was because no efficient online payment system existed for securely processing very small transactions at large volumes. (Credit-card systems are too expensive and clumsy for small transactions.) But the absence of a micro-payment system led to the evolution of the web in a dysfunctional way: companies offered "free" services that had a hidden and undeclared cost, namely the exploitation of the personal data of users. This led to the grossly tilted playing field that we have today, in which online companies get users to do most of the work while only the companies reap the financial rewards.

19 We thought that the HTTPS protocol would make the web secure. We were wrong

HTTP is the protocol (agreed set of conventions) that normally regulates conversations between your web browser and a web server. But it's insecure because anybody monitoring the interaction can read it. HTTPS (stands for HTTP Secure) was developed to encrypt in-transit interactions containing sensitive data (eg your credit card details). The Snowden revelations about US National Security Agency surveillance suggest that the agency may have deliberately weakened this and other key internet protocols.

20 The web has an impact on the environment. We just don't know how big it is

The web is largely powered by huge server farms located all over the world that need large quantities of electricity for computers and cooling. (Not to mention the carbon footprint and natural resource costs of the construction of these installations.) Nobody really knows what the overall environmental impact of the web is, but it's definitely non-trivial. A couple of years ago, Google claimed that its carbon footprint was on a par with that of Laos or the United Nations. The company now claims that each of its users is responsible for about eight grams of carbon dioxide emissions every day. Facebook claims that, despite its users' more intensive engagement with the service, it has a significantly lower carbon footprint than Google.

21 The web that we see is just the tip of an iceberg

The web is huge – nobody knows how big it is, but what we do know is that the part of it that is reached and indexed by search engines is just the surface. Most of the web is buried deep down – in dynamically generated web pages, pages that are not linked to by other pages and sites that require logins – which are not reached by these engines. Most experts think that this deep (hidden) web is several orders of magnitude larger than the 2.3 billion pages that we can see.

22 Tim Berners-Lee's boss was the first of many people who didn't get it initially

Berners-Lee's manager at Cern scribbled "vague but interesting" on the first proposal Berners-Lee submitted to him. Most people confronted with something that is totally new probably react the same way.

23 The web has been the fastest-growing communication medium of all time

One measure is how long a medium takes to reach the first 50 million users. It took broadcast radio 38 years and television 13 years. The web got there in four.

24 Web users are ruthless readers

The average page visit lasts less than a minute. The first 10 seconds are critical for users' decision to stay or leave. The probability of their leaving is very high during these seconds. They're still highly likely to leave during the next 20 seconds. It's only after they have stayed on a page for about 30 seconds that the chances improve that they will finish it.

25 Is the web making us stupid?

Writers like Nick Carr are convinced that it is. He thinks that fewer people engage in contemplative activities because the web distracts them so much. "With the exception of alphabets and number systems," he writes, "the net may well be the single most powerful mind-altering technology that has ever come into general use." But technology giveth and technology taketh away. For every techno-pessimist like Carr, there are thinkers like Clay Shirky, Jeff Jarvis, Yochai Benkler, Don Tapscott and many others (including me) who think that the benefits far outweigh the costs.

John Naughton's From Gutenberg to Zuckerberg is published by Quercus