In general, a network is a collection of objects connected to each other in some fashion.
The science of networks: constructing a language for talking about networks that is precise enough to describe not only what a network is but also what kinds of networks there are in the world.
In mathematics, a network is a graph. But in traditional graph theory, networks have been viewed as objects of pure structure whose properties are fixed in time. But real networks represent populations of individual components that are actually doing something.
“Networks are also dynamic objects not just because things happen in networked systems, but because the networks themselves are evolving and changing in time, driven by the activities or decisions of those very components. In the connected age, therefore, what happens and how it happens depend on the network. And the network in turn depends on what has happened previously.
It s this view of a network – as an integral part of a continuously evolving and self-constituting system – that is truly new about the the science of networks. ” (from Duncan Watts)
Physicists and mathematicians have analytical and computational skills. Sociologists, psychologists and anthropologists have thought deeply about the relationship between networks and society – thinking that is now turning out to be relevant to surprising range of problems from biology to engineering.