Bulges lie at the heart of most galaxies, the building blocks of our universe. With a selection of reviews and topical presentations, IAU Symposium 245 provides an up-to-date overview of our knowledge on galaxy bulges, and a concise introduction to all current research on the subject. The structure, dynamics, and stellar populations of galaxy bulges, both near and far, are analysed through state-of-the-art observations. The leading models for the formation and evolution of galaxy bulges are described in detail, and the constraints observations put on these are dissected. Particular emphasis is placed on exploring evidence for both hierarchical merging and secular processes. Special attention is also devoted to disentangling the complex web relating galaxy bulges and central supermassive black holes, and on the lessons learned from our exquisite knowledge of the bulge of our own Milky Way. This volume is the best one-stop reference on galaxy bulges currently available.