Transesterification is a chemical process that converts fats or oils into biodiesel and glycerol. This reaction involves the exchange of ester groups between triglycerides (fats and oils) and an alcohol, typically methanol or ethanol. The result is biodiesel, which can be used as a renewable energy source, and glycerol, a valuable byproduct used in various industries. The process usually requires a catalyst, such as sodium hydroxide or potassium hydroxide, to speed up the reaction. Transesterification is essential for producing biodiesel from sources like vegetable oils and animal fats, making it an important step in the development of sustainable energy alternatives.