  The study of temporal networks is motivated by the simple and important
observation that just as network structure can affect dynamics, so can
structure in time. Just as network topology can teach us about the system in
question, so can its temporal characteristics. In many cases, leaving out
either one of these components would lead to an incomplete understanding of the
system or poor predictions. We argue that including time into network modeling
inevitably leads researchers away from the trodden paths of network science.
Temporal network theory requires something different -- new methods, new
concepts, new questions -- compared to static networks. In this introductory
chapter, we overview the ideas that the field of temporal networks has brought
forward in the last decade. We also place the contributions to the current
volume on this map of temporal-network approaches.
