It is a mixture of two immiscible liquids (which do not mix). The most liquid is the dispersant and the least liquid is the dispersed one, distributed in very small diffused droplets in suspension.
Thus, emulsion is a colloidal dispersion in which both the dispersing phase and the dispersed phase are in the liquid phase. That is, emulsions consist of a colloid in which small particles of one liquid are dispersed in another liquid.
The expression emulsion comes from Latin emulsu which means milked due to the milky appearance of most emulsions.
Emulsions are unstable, but some substances may act as emulsifiers, giving emulsion stability.
An emulsion has long chain and atoms attached with one polar end and the other apolar end, as well as detergent and soap molecules.
Some emulsions: milk, creams, mayonnaise.