A common property of Web 2.0 technologies is that they facilitate collabora-
tion and sharing between users with low technical barriers – although usually on
single sites (e.g. Technorati) or with a limited range of information (e.g. RSS,
which we will describe later). In this book we will refer to this collaborative and
sharing aspect as the ‘Social Web’, a term that can be used to describe a subset of
Web interactions that are highly social, conversational and participatory. The So-
cial Web may also be used instead of Web 2.0 as it is clearer what feature of the
Web is being referred to4.