The developing brain generates spontaneous activity even before our senses are activated. This spontaneous activity is transmitted along neuronal pathways and is required for setting up precise connections between nerve cells. How specific activity patterns are translated into precise patterns of connectivity is currently unknown. To start addressing this question, we are investigating the patterns of spontaneous activity in the developing visual cortex using in vivo calcium imaging and electrophysiology. We discovered two types of spontaneous activity that are characterized by low and high levels of synchronization between neurons: L- and H-events, respectively. Manipulating peripheral spontaneous activity, i.e. retinal waves shows that L-events are largely driven by retinal inputs. In contrast, H-events are centrally generated. Here, I will discuss the characteristics of these activity patterns from the synaptic to the network level and propose ideas about how these activity patterns may guide the development of specific connections in the developing visual system.