It has long been known that bacteria, viruses, and eukaryotes such as fungi and arthropods inhabit the skin. However, the community of microorganisms on human skin is more complex than once thought. Understanding the composition of the skin microbial community is a significant advance from older classifications of cutaneous microbiota that focused on skin microbes only as pathogens or opportunistic pathogens, and has come from the development of methods based on sequencing technologies that are independent of the need for cultivation of microbes. This new information has revealed that the composition of the skin microbiome is diverse and loosely organized and varies for different skin locations. Most importantly, more recent descriptions of the composition of the skin microbiome have inspired new work towards understanding the functional significance of resident microbes on the skin, and have led to important new advances in our understanding of both normal physiology and disease.