Sucrose is formed by combination of fructose and glucose. This is the cane sugar that you put in your coffee or on your breakfast cereal. See figure 2.1 on page 25. Lactose is formed by combination of glucose and fructose. This is the sugar found in milk.
Some folks are lactose intolerant.
Maltose is formed by combination of 2 glucose molecules. This is a breakdown product from the malting process required in the brewing industry. Polysaccharides are formed when an endless chain of monosaccharides are linked together. The chains can even be branched. Starch is a major energy storage molecule.