Biosurfactants are surface-active secondary metabolites, produced by microorganisms, such as bacteria, fungi, and yeasts. Biosurfactants have been identified as an alternative approach to chemical surfactants due to its remarkable characteristics such as eco-friendliness, biological protection, biodegradability, and lower toxicity. Initially, it was suggested that biosurfactants could serve as emulsifiers of biodegradable hydrocarbons. However, later on, many studies have explained clearly their multi properties, such as antimicrobial, anti-adhesive, and antioxidant. This has widened the applications of biosurfactants in many fields including; petroleum, agriculture, food production, chemistry, cosmetics and pharmaceutics etc. This review outlined the structural characterization, classification, properties, biosynthesis, and mechanism of action. As well, considerable space is given to emphasise their potential applications along with recent developments. Since, commercial productions of biosurfactants are expensive, future research should be targeted to find alternative and cost-effective raw materials (carbon sources) to cut down the production cost. Sources of most biosurfactants are restricted into several groups of terrestrial microorganisms, more research works need to be focused on targeting different other microbial populations, including, marine dwellings to find novel biosurfactants.