First and foremost, the ecological system under normal physiological conditions must maintain homeostasis between the microbiome and host. The mechanisms responsible for this balance remain largely unknown, and have been complicated by observations showing that the exact composition of skin microbes varies from individual to individual, but remains somewhat stable over time 1 and 2. Furthermore, the relevant interactions that define this cutaneous system are not limited to those between the microbe and the host. The skin is unique among epithelial surfaces in terms of complex ecological interactions with the environment. In addition, competition within and between microbial species is important for the development and maintenance of a healthy microbiome. This review provides an update on some of the current information describing the skin microbiome and experimental advances towards better understanding of the biology and significance of this important system.