Prokaryotes exhibit remarkable desiccation tolerance, a trait observed in bacteria, plants, insects, and other organisms. This review explores the water relations and theoretical considerations underlying desiccation tolerance in prokaryotes. Water is essential for cellular processes, influencing structure, function, and stability of proteins, nucleic acids, and lipids. The properties of water, including its high heat of vaporization and hydrogen bonding, play a critical role in cellular water dynamics. Water potential, osmotic pressure, and matric water potential are key factors in understanding how cells respond to water stress. Desiccation can lead to significant physiological stress, with varying degrees of tolerance among prokaryotes. The removal of water from cells can occur through various methods, including drying, salting, or sugaring, each affecting cells differently. The desiccation process can damage cellular components such as proteins, nucleic acids, and membranes, with the extent of damage depending on the type of cell and the desiccation method used. Prokaryotes have developed various mechanisms to tolerate desiccation, including physiological adaptations such as the production of compatible solutes like trehalose, and structural adaptations such as the formation of protective sheaths or capsules. These mechanisms help maintain cellular integrity and function during desiccation and rehydration. The ecological significance of desiccation tolerance is evident in the ability of prokaryotes to survive in extreme environments, such as deserts or high altitudes. The study of desiccation tolerance in prokaryotes has important implications for biotechnology, including the development of stable enzymes and cells for industrial applications. Understanding the mechanisms of desiccation tolerance in prokaryotes can provide insights into the broader principles of cellular survival and adaptation.Prokaryotes exhibit remarkable desiccation tolerance, a trait observed in bacteria, plants, insects, and other organisms. This review explores the water relations and theoretical considerations underlying desiccation tolerance in prokaryotes. Water is essential for cellular processes, influencing structure, function, and stability of proteins, nucleic acids, and lipids. The properties of water, including its high heat of vaporization and hydrogen bonding, play a critical role in cellular water dynamics. Water potential, osmotic pressure, and matric water potential are key factors in understanding how cells respond to water stress. Desiccation can lead to significant physiological stress, with varying degrees of tolerance among prokaryotes. The removal of water from cells can occur through various methods, including drying, salting, or sugaring, each affecting cells differently. The desiccation process can damage cellular components such as proteins, nucleic acids, and membranes, with the extent of damage depending on the type of cell and the desiccation method used. Prokaryotes have developed various mechanisms to tolerate desiccation, including physiological adaptations such as the production of compatible solutes like trehalose, and structural adaptations such as the formation of protective sheaths or capsules. These mechanisms help maintain cellular integrity and function during desiccation and rehydration. The ecological significance of desiccation tolerance is evident in the ability of prokaryotes to survive in extreme environments, such as deserts or high altitudes. The study of desiccation tolerance in prokaryotes has important implications for biotechnology, including the development of stable enzymes and cells for industrial applications. Understanding the mechanisms of desiccation tolerance in prokaryotes can provide insights into the broader principles of cellular survival and adaptation.