An emulsion is a mixture of two liquids that usually do not mix well, such as oil and water. In an emulsion, tiny droplets of one liquid are dispersed throughout the other, creating a stable blend. Common examples include mayonnaise and salad dressings, where emulsifiers help keep the mixture uniform. Emulsifiers are substances that help stabilize emulsions by reducing the surface tension between the two liquids. They can be natural, like egg yolk in mayonnaise, or synthetic, like monoglycerides in processed foods. Emulsions are important in cooking, cosmetics, and pharmaceuticals for their unique properties.