What is the semantic web?

Tim Berners-Lee describes it in his blog post Giant Global Graph (from 2007-11-21):

Three mental moves:

1. Internet: "It isn't the cables, it is the computers which are interesting"
2. (World Wide) Web: "It isn't the computers, but the documents which are interesting"
3. Giant Global Graph: "It's not the documents, it is the things they are about which are important"

About the term "Giant Global Graph":

We can use the word Graph, now, to distinguish from Web.

I called this graph the Semantic Web, but maybe it should have been Giant Global Graph! Any worse than WWWW? ;-) Not the "Semantic Web" term has been established for a long time, I'm not proposing to change it. But let's think about the graph which it is. (Footnote: "Graph" also happens to be the word the RDF specifications use, but that is by the way. While an XML parser creates a DOM tree, an RDF parser creates an RDF graph in memory.)

It's a buzz word to attract people's interest, Similiar to Web 2.0

I.e. In the future content will be split from presentation allowing much goodness.
In reality Facts will be subjective, depending on the realibility and authority of the host.

In other words, users won't see much difference from now.