Biosurfactants are a varied class of amphiphilic compounds primarily synthesized by microorganisms which exhibit remarkable surface-active properties. Biosurfactants are environmentally friendly, biodegradable agents that remain efficient even under extreme temperature, pH, and salinity conditions, making them promising sustainable alternatives to conventional synthetic surfactants. This review highlights the physicochemical behavior of biosurfactants, focusing on their ability to reduce surface and interfacial tensions, form micelles and emulsions, and increase the accessibility and solubility of hydrophobic compounds. Particular attention is given to their impact on microbial cell surfaces, membrane interactions, and their role in processes such as biofilm disruption and pollutant degradation. Additionally, the paper discusses the expanding industrial and environmental applications of biosurfactants, including bioremediation, wastewater treatment, enhanced oil recovery, food processing, agriculture, and medical therapeutics. They are promising sustainable substitutes for synthetic surfactants, highlighted by the rising market demand, technological advancements in fermentation, and the utilization of renewable substrates. Overall, biosurfactants represent a promising class of biomolecules that bridge environmental responsibility with industrial innovation.