Carbohydrates which yield a large number of monosaccharide units on hydrolysis are called polysaccharide. Some common examples are starch, cellulose, glycogen, gums etc.
Polysaccharide are not sweet in taste hence, they are called non-sugars. They are classified as either reducing or non-reducing sugar. All those carbohydrates which reduce Fehling's solution and Tollen's reagent are referred to as reducing sugars. All monosaccharides whether aldose or ketose are reducing sugars.