What is the difference between oil/water (O/W) type and water/oil (W/O) type emulsions?

In an oil-in-water emulsion, the continuous phase is the water and the dispersed phase is the oil while in a water-in-oil emulsion the oil is the continuous phase. Oil-in-water emulsions are common in food products. a. Cream (foam) in espresso – coffee oil in water (brewed coffee). b. Homogenized milk – an emulsion of milk fat in water and milk proteins. Water-in-oil emulsions are less common in food. c. Butter – an emulsion of water in butterfat.