Emulsion is known as a colloidal solution of two liquids. A colloidal solution is a mixture where one substance is dispersed in another substance, with the particles of the dispersed substance being larger than individual molecules but smaller than what is considered a bulk solid. In an emulsion, the liquid that is dispersed is usually referred to as the "dispersed phase" and the liquid in which it is dispersed is called the "continuous phase".

Emulsions can be found in various everyday products, such as milk, mayonnaise, and salad dressings. These products have a creamy or thick consistency due to the presence of an emulsion. The stability of an emulsion is often enhanced with the use of emulsifiers, which help to keep the dispersed particles from separating and settling.

It is important to note that emulsions are not the same as solutions, where one substance is fully dissolved in another. In an emulsion, the dispersed phase and the continuous phase remain distinct and may separate over time. Emulsions can be unstable and may require shaking or stirring to maintain their uniformity.