Recent years have seen significant advances in mapping structural and functional brain connectivity across several species, including humans. Common features of brain networks encountered in numerous studies are network modules (clusters of densely connected network elements) and hubs (nodes that are highly connected, central or vulnerable). The potentially important roles of modules and hubs are highlighted by the consideration of “communication dynamics” – the ebb and flow of information within the overall network. This talk will focus on the structural and functional roles of network modules and hubs in brain networks. I will discuss how hubs are defined and detected in structural and functional network data, and what predictions network models make about their contribution to signalling and communication processes. I will review recent work on how brain hubs are linked into “cores” or “rich clubs” and what this type of network architecture can tell us about integrative brain function. I will end with a discussion of how a better understanding of brain networks may provide new insights into the network basis of human individuality and variation.