Book excerpt: Dense stellar systems lie at the interface between dynamics, stellar evolution, and galaxy formation, and they provide us with an ideal laboratory to understand many different aspects of these important fields as well as to explore the interplay between them. The complete study of dense stellar systems is a very challenging task which requires the collaboration and the exchange of ideas of astronomers and physicists with observational and theoretical expertise in galactic and extra-galactic astronomy, stellar dynamics, hydrodynamics, stellar evolution, as well as knowledge of many aspects of computational physics. IAU Symposium 246 brought together experts in all these areas to cover the broad field of dense stellar systems with particular emphasis on the interplay between them and on the comparison between observations and simulations. This volume provides a complete review of the most recent studies in this topical research.