An emulsion may be understood as a combination of two or more liquids in a suspended state, as these liquids would not ordinarily tend to dissolve in one another under standard conditions of temperature and pressure. While this might not appear to be a regular state of matter, the fact is that emulsions exist in our natural environment more commonly than we would probably think. Several food products are basically emulsions or colloids, the latter being a slight variation of the former, in which particles of a solid are suspended in a liquid. Milk for instance is a combination of particles of fat dispersed in a liquid medium. The yolk of an egg in the untreated state is also an emulsion.
Artificial products of daily use are very frequently packaged and marketed as emulsions. Most cosmetic items such as creams, gels, other personal care items such as toothpaste, and all pharmaceutical ointments that are applied on the skin are basically emulsions. Even some vaccines and more dilute fluids that are taken as oral medication are also examples of these suspended state compounds.
Calling an emulsion a compound is also a bit of a technical error. A chemical compound is formed when the ingredient elements react to form something totally new, the resultant having its own set of physical and chemical characteristics that are different from those of its parent element. In a colloid or emulsion on the other hand, the individual ingredients continue to exist as they were, and the resultant is just a physical combination of these particles in a dispersed state. Thus, the characteristics of the parent ingredients are retained. This in turn implies that emulsions have now become the natural choice of medium for medical and cosmetic usage, as they allow the required components to safely exist together in one state without reacting mutually and thereby transforming into something different.
Seeing this extreme demand for artificially manufactured emulsions today, machines that allow these to be generated in bulk have been developed. Such systems are known as vacuum homogenizer emulsifiers, and are made up of a series of steel tanks in which ingredients are loaded, agitated and blended by means of centrifugal force and changes in heat settings. These emulsifiers are optimized for smartness and efficiency, and include several presets that can be programmed as well, so that a particular process can be successfully repeated without reiteration of effort.