The process of converting sugar to alcohol by yeast is called fermentation. This anaerobic metabolic process allows yeast to break down glucose in the absence of oxygen, producing ethanol and carbon dioxide as byproducts. Fermentation is crucial in various industries, most notably in the production of alcoholic beverages, bread, and biofuels. In winemaking and brewing, fermentation not only contributes to flavor development but also serves as an important means of preserving products by inhibiting spoilage microbes, showcasing its economic and cultural significance.