by Tim Berners-Lee
Progress in communications technology has been characterized by a movement from lower to higher levels of abstraction. When, first, computers were connected by telephone wires, you would have to run a special program to make one connect to another. Then you could make the second connect to a third, but you had to know how to use the second one too. Mail and news was passed around by computers calling each other late at night, and, for a while, email addresses contained a list of computers to pass the message through, such as: timbl@mcvax!cernvax!cernvms.
It's not the wires - it's the computers
The ability to use this communication power between computers wasn't truly useful until the Internet. The Internet allowed one to forget about the individual connections. It was thought of as the 'Internet Cloud'. Messages went in from one computer, and appeared in another, without one having to worry about how they were broken into packets, and how the packets were routed from computer to computer.
by Lynda Hardman and Steven Pemberton
The Sapir-Whorf Hypothesis postulates a link between thought and language: if you haven't got a word for a concept, you can't think about it; if you don't think about it, you won't invent a word for it. The term "Web 2.0" is a case in point. It was invented by a book publisher as a term to build a series of conferences around, and conceptualises the idea of Web sites that gain value by their users adding data to them. But the concept existed before the term: Ebay was already Web 2.0 in the era of Web 1.0. But now we have the term we can talk about it, and it becomes a structure in our minds, and in this case a movement has built up around it.