The human skin microbiome is a complex community of bacteria, fungi, and viruses that live on the skin and play essential roles in protecting against pathogens, educating the immune system, and breaking down natural products. The skin, as the largest organ of the body, serves as a physical barrier and is colonized by beneficial microorganisms. However, when this barrier is compromised or the balance between commensals and pathogens is disrupted, skin diseases or even systemic diseases can occur. Skin sites can be categorized based on their physiological characteristics, such as sebaceous (oily), moist, or dry environments. Understanding the composition of the skin microbiota at different sites is crucial for elucidating the causes of common skin disorders, which often prefer specific skin sites. Traditional methods for studying skin microbial communities, such as culture-based approaches, have limitations in capturing the full diversity of the microbiome. Therefore, sequencing methods, including amplicon and shotgun metagenomic sequencing, have been developed to provide more comprehensive insights. Amplicon sequencing focuses on conserved marker genes, while shotgun metagenomics captures all genetic material in a sample, allowing for the analysis of kingdom-level abundances and strain-level resolution. These methods have revealed that the skin microbiota is largely stable over time, with variations primarily due to individual differences rather than environmental changes. The skin microbiota is influenced by factors such as skin physiology, environmental conditions, and individual characteristics. For example, sebaceous sites are dominated by Propionibacterium species, while moist sites have higher abundances of Staphylococcus and Corynebacterium. Fungal communities are more similar across core body sites, with Malassezia being predominant in core body and arm sites. The skin microbiome is also shaped by interactions between microorganisms and the immune system, with some species playing roles in colonization resistance and disease pathogenesis. In diseases such as atopic dermatitis and acne, changes in the microbiota (dysbiosis) are associated with altered microbial communities. For instance, Staphylococcus aureus is a significant contributor to atopic dermatitis, while Propionibacterium acnes is linked to acne. Understanding these microbial interactions is crucial for developing therapeutic strategies targeting the skin microbiome. Future research aims to explore the functional roles of different microbial strains and their interactions with the immune system to improve treatments for skin diseases.The human skin microbiome is a complex community of bacteria, fungi, and viruses that live on the skin and play essential roles in protecting against pathogens, educating the immune system, and breaking down natural products. The skin, as the largest organ of the body, serves as a physical barrier and is colonized by beneficial microorganisms. However, when this barrier is compromised or the balance between commensals and pathogens is disrupted, skin diseases or even systemic diseases can occur. Skin sites can be categorized based on their physiological characteristics, such as sebaceous (oily), moist, or dry environments. Understanding the composition of the skin microbiota at different sites is crucial for elucidating the causes of common skin disorders, which often prefer specific skin sites. Traditional methods for studying skin microbial communities, such as culture-based approaches, have limitations in capturing the full diversity of the microbiome. Therefore, sequencing methods, including amplicon and shotgun metagenomic sequencing, have been developed to provide more comprehensive insights. Amplicon sequencing focuses on conserved marker genes, while shotgun metagenomics captures all genetic material in a sample, allowing for the analysis of kingdom-level abundances and strain-level resolution. These methods have revealed that the skin microbiota is largely stable over time, with variations primarily due to individual differences rather than environmental changes. The skin microbiota is influenced by factors such as skin physiology, environmental conditions, and individual characteristics. For example, sebaceous sites are dominated by Propionibacterium species, while moist sites have higher abundances of Staphylococcus and Corynebacterium. Fungal communities are more similar across core body sites, with Malassezia being predominant in core body and arm sites. The skin microbiome is also shaped by interactions between microorganisms and the immune system, with some species playing roles in colonization resistance and disease pathogenesis. In diseases such as atopic dermatitis and acne, changes in the microbiota (dysbiosis) are associated with altered microbial communities. For instance, Staphylococcus aureus is a significant contributor to atopic dermatitis, while Propionibacterium acnes is linked to acne. Understanding these microbial interactions is crucial for developing therapeutic strategies targeting the skin microbiome. Future research aims to explore the functional roles of different microbial strains and their interactions with the immune system to improve treatments for skin diseases.