  The study of synchronization of coupled systems is currently undergoing a
major surge fueled by recent discoveries of new forms of collective dynamics
and the development of techniques to characterize a myriad of new patterns of
network synchronization. This includes chimera states, phenomena determined by
symmetry, remote synchronization, and asymmetry-induced synchronization. This
Focus Issue presents a selection of contributions at the forefront of these
developments, to which this introduction is intended to offer an up-to-date
foundation.
