Emulsion stability refers to the ability of an emulsion, a mixture of two immiscible liquids like oil and water, to remain uniform over time. Factors such as temperature, concentration, and the presence of emulsifiers can influence this stability. Emulsifiers, which are substances that help to stabilize emulsions, reduce the surface tension between the two liquids, preventing them from separating. When an emulsion is unstable, it can lead to phase separation, where the oil and water layers separate. This instability can be affected by changes in pH, temperature, or the addition of salt. Understanding emulsion stability is crucial in various industries, including food, cosmetics, and pharmaceuticals.