The most common form of this sugar is dextroglucose, a naturally occurring form generally referred to as dextrose (also called corn sugar and grape sugar). This form of glucose has many sources including grape juice, certain vegetables and honey. It has about half the sweetening power of regular sugar. Because it doesn't crystallize easily, it's used to make commercial candies and frostings, as well as in baked goods, soft drinks and other processed foods. Corn syrup is a form of glucose made from cornstarch.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.