network_science_december_ch4_2013

As difficult it is to overstate the importance of the World Wide Web in

our daily life, it is equally hard to exaggerate the role the Web played in

the development of network theory. It aided the discovery of a number of

fundamental network properties and became a standard testbed for many

network measures. As its name states, the WWW is a “web” whose nodes

are documents and the links are the uniform resource locators (URLs) that

allow us to move with a click from one web document to the other. With

an estimated size of over one trillion documents (N≃1012

), the Web is the

largest network humanity has ever built. It exceeds in size even the human

brain (N ≃ 1011

neurons).