Fatty acid esters (FAEs) are a type of ester that result from the combination of a fatty acid with an alcohol. When the alcohol component is glycerol, the fatty acid esters produced can be monoglycerides, diglycerides, or triglycerides, all of which are components of vegetable fats and oils.
Biodiesels are typically fatty acid esters produced by the transesterification of vegetable fats and oils which results in the replacement of the glycerol component with a different alcohol.