The chapter "Biofilms: Microbial Life on Surfaces" by Rodney M. Donlan provides an in-depth overview of biofilms, which are communities of microorganisms that adhere to surfaces and form structured ecosystems. These biofilms are characterized by the production of an extracellular polymeric substance (EPS) matrix, reduced growth rates, and differential gene expression compared to planktonic cells. The attachment process is influenced by various factors, including the growth medium, substratum characteristics, and cell surface properties. Biofilms have significant implications for public health, particularly in the context of infectious diseases and device-related infections. The chapter discusses the historical basis of biofilm research, the definition and structure of biofilms, the role of hydrodynamics and conditioning films in attachment, and the complex interactions within biofilms, such as gene regulation, quorum sensing, and predation. It also highlights the importance of biofilms in antimicrobial resistance and chronic diseases, and outlines future research directions to better understand and control biofilm formation.The chapter "Biofilms: Microbial Life on Surfaces" by Rodney M. Donlan provides an in-depth overview of biofilms, which are communities of microorganisms that adhere to surfaces and form structured ecosystems. These biofilms are characterized by the production of an extracellular polymeric substance (EPS) matrix, reduced growth rates, and differential gene expression compared to planktonic cells. The attachment process is influenced by various factors, including the growth medium, substratum characteristics, and cell surface properties. Biofilms have significant implications for public health, particularly in the context of infectious diseases and device-related infections. The chapter discusses the historical basis of biofilm research, the definition and structure of biofilms, the role of hydrodynamics and conditioning films in attachment, and the complex interactions within biofilms, such as gene regulation, quorum sensing, and predation. It also highlights the importance of biofilms in antimicrobial resistance and chronic diseases, and outlines future research directions to better understand and control biofilm formation.