Fructose is a monosaccharide and ketohexose sugar commonly found in fruits, honey, and many vegetables. It is one of the three dietary monosaccharides absorbed directly into the bloodstream during digestion, along with glucose and galactose. Fructose has a higher sweetness intensity than glucose or sucrose and is often used as a sweetener in processed foods and beverages. Chemically, it exists in equilibrium between open-chain and cyclic forms (furanose and pyranose) in solution. It plays a central role in carbohydrate metabolism via the polyol pathway and fructolysis in the liver. Excessive intake has been linked to metabolic effects including increased hepatic fat accumulation, though it remains a key natural component of the human diet.