Synchronization is a ubiquitous phenomenon, universally found both in natural and human-engineered systems: from firing neurons to the twinkling of fireflies, from metronomes to power grids, from applauding audiences to the circadian rhythms of plants and animals. Patterns and order magically emerge from the disordered interplay of many interacting parts, with a complexity which seems to give no hope for simple models. The Kuramoto model is one of the hallmarks of complex systems’ theory, with its simplicity, richness of behavior and surprising modeling power. It allows us to describe the onset of synchronization in systems of oscillators which interact in pairs according to a determined network topology.